Help! I need improvements...

So I've had the Lenovo Y50-70 touch as my gaming laptop for about 3 years ( It said it was made 15/08/15 to be exact). by now, it struggles to handle certain games I have, and while that partly might be the WiFi's fault, I need a better computer. I bought a gaming laptop so I could still play with my friends while I traveled, but we barely travel anymore and it due to how busy everyone is (work, my brother in college so our break times our different, etc.). Instead I'm looking to make a gaming PC this time around. I have a friend that knows a lot more than me about building PC's. He volunteers at some computer shop and has built one for himself, and he said he would build one for me for free. He even offered to help find parts with me, but I want a second opinion from people who know about PC's. I'm going to go through each of the parts I need and preferences for the ones I know about. Any help would be appreciated, thanks a bunch!

Mouse- I want a left handed ergonomic mouse, because I struggle to reach the side buttons of a mouse with my pinky and find my hand cramping up/bothering me after 1-2 hours online of gaming.

Monitor- I am really disappointed with the monitor on this laptop. I want it to be decently sized so I can see stuff far away in games, but I don't want it taking all of my desk space. I want it to be able to handle 4k and the screen to be good looking with a not stand-out border, because the what you always look at.

Case- I DO NOT care how the case looks. I don't plan on wanting any accessories/styles, I'm just putting it under my desk. It doesn't matter as long as it fits all of the parts needed inside and doesn't bother how it sit. (in opinion, length-1ft, height-18in, depth-24in, or smaller for depth+height if it can fit the parts)

Storage- Want at least 1 terabyte, maybe 1.5 to be safe

GPU(Graphics Processing Unit), CPU(Processor), Motherboard, Memory, Power Supply Unit (PSU)- I don't know anything about these so I'm all ears. All i know if that these can become the really expensive parts easily and that the motherboard needs to accomadate all of them.

Again, Thanks so much in advance. I'm really looking forward to improving to something better than this laptop.

@yaboi22:

For a left handed mouse Razer DeathAdder essential left handed mouse LINK

@yaboi22: This really depends on you're budget, if you want the best computer possible it can cost over $10,000.

@npiet1: I'd like to spend $1,000 but I'd probably go and cap it at $2-3,000. I don't need something phenomenal, just mainly a good monitor and mouse, and the rest aren't as important but obviously essential.

@04dcarraher: Thanks! I'll look at the right now, because I'm getting that even while I have this laptop.

@yaboi22: PC's cant do 4k, you can get a 4k monitor, but you wont be playing on high/ultra or whatever, it'll be medium to maintain 60fps.

@yaboi22: You'll need to wait for the gtx 1180 which is rumoured for july for 4k. which is around $700 (us). Then a decent 4k monitor is another $600(us).

AMD Ryzen 7 2700X 8 Core Socket AM4 4.35GHz ($450 aud)

32gb ddr4 ram ($500 aud)

Samsung evo 960 500gb m.2 ssd ($280 aud) This runs OS and current games

WD Black 2tb ($170 aud) Storage

Mortar Artic Mobo ($125 aud) its the one I have,

PSU is your choice just make sure its atleast 750W around (100Aud)

Case is your choice just make sure that the form factor is ATX (around $100 aud however can be upto $300 aud depending on your style)

$2000 (US) for the computer but that's a beast. The 1180 should handle 4k I don't know if you'll get ultra though.Its also not going to be this price but a bit cheaper as i used my aus store for prices and most other hardware store are cheaper

@npiet1: Thanks a bunch! I'm going to show my friend all you recommended and then we'll work from there.

@npiet1: Just wondering, you say $2000 but with all of this combined it would be $3125 with everything you listed. I haven't had much time to look at everything individually but now that I've just started summer break I've gotten as far as a way to get most of the money over my break (except for $2000 not $3125). Are you just assuming that the prices can be haggled down this low or was it some typo? Thanks!

I wasn't counting the monitor. Its also cause I counted in AUD for all except GPU, Then converted it to us dollars. Then on top of that because I'm Aussie I tend to pay a bit more money than what you would (assuming your in the US) like Amazon you'll find these parts for a lot cheaper

@npiet1: okay thanks for clarifying. I am in the US. I might even look for cheaper parts than Amazon though on some used parts apps (unless these are too new to find used for) and I might even get the case for free from one of my friends. in your opinion does this mouse look good? I'm a lefty so I want to switch to a left-handed mouse and vertical mouses are supposed to be better for cramps (which I have been starting to get) along with the fact that it is ergonomic. I know that @04dcarraher recommended a razor mouse but I have looked at reviews and complaints have been going on about the mouse's software, along with the fact that there are less positive reviews based off of recent cements on the product. The only thing holding me back is the reaction time(DPI), which is apparently very good with the razor. I am looking at the one in the link below because it is supposed to be very comfortable, good for the hand, is wireless (which i have right now and prefer over wired), and I don't care much for the colors so it doesn't seem worth $35 more dollars than the one below.

https://www.amazon.com/Left-Handed-Jelly-Comb-Wireless-Ergonomic/dp/B07BGZVD4B/ref=sr_1_1_sspa?ie=UTF8&qid=1527744390&sr=8-1-spons&keywords=left+handed+ergonomic+wireless+mouse&psc=1

Also, sorry for asking so many questions, but how much do you think I could sell my Lenovo Y50-70 Touch for?

@yaboi22: I couldn't give you an opinion on those mice, I never use one. they are more ergonomic though. I've never worried about DPI, it's one of those things where hardcore gamers will say theres a difference but no one really does. I'm a lefty too, I had to get use to using a right mouse cause of my family. I use a cheap Logitech one, to me a mouse is a mouse. Keyboards are a bit different though.

With used parts the only thing I would say is never get the Hard drive second hand. I've gotten a lot of 2nd hand HDD's before and there's been some weird stuff on them lol, I've had to hand one in to the cops as well.

The laptop there selling for $300 us on ebay so around that you could ask for $400 on facebook though and might get lucky. Its still a pretty decent laptop.

Any more questions don't be afraid to ask, I like helping people.

@yaboi22:

Here is another option for a mouse https://www.amazon.com/Logitech-G300s-Optical-Ambidextrous-Gaming/dp/B00RH6R7C4/ref=sr_1_1?s=electronics&ie=UTF8&qid=1528123659&sr=1-1&keywords=logitech+g300s