Help with first build?

Hey, recently decided I'd finally get a decent PC. Quite frankly I know very little about what I'm doing.

A friend has recommended some parts and has offered help to build it; just wanted to check that these parts will all be compatible and the thing will actually work, so any help is appreciated.

CPU - i5 2500K

GPU - GTX 560 TI

RAM - Kingston HyperX 8GB DDR3 1600MHz Kit

PSU - Antec Neo Eco 620w

Mobo -ASRock Z68 Extreme3 Gen3

HDD - Seagate Barracuda 7200RPM SATA

Case - CM Scout

DVD Drive

Will this stuff be okay, anything I've missed (discluding OS, monitor, KB/M)? Is there anything you would recommend over any of these particular parts, on a similar budget?

Thank you.

I don't think it will turn into a bad rig. If you're going for gaming I'd shell out a little more toward a gpu upgrade :) That's my 2 cents :D

And for a little more you can get a Corsair PSU :D

http://www.scan.co.uk/products/650w-psu-corsair-enthusiast-series-650txv2uk-85-eff-80-plus-bronze-sli-crossfire-eps-12v-quiet-fan-a

Okay; yeah I was planning on playing games on it, what card would you recommend in it's place? I'm trying not to spend a great deal (£600~ with the listed set-up), but I'll consider an upgrade if it's worth it.

Also what advantages does the ASrock Z77 Extreme 4 have over the ASRock Z68 Extreme3 Gen3?