Deciding on next upgrade

So I am able to upgrade my gaming computer and I want to make the smartest choice.

The overall budget is 350-400 dollars, but 400 is really pushing it heh.

Here are my current specs.

Mobo-ASUS rampage formula mobo

CPU-intel core 2 duo e6850 at 3 ghz

Memory-4gb of ddr2 ram from g.skill

PSU-corsair 750watt psu

Video Card-Geforce 9800 gtx+ 512 mb

OS-Windows 7 32 bit

Monitor-Dell SP2008WFP 19 inch monitor

My first idea is that with my monitor I can't go to 1080 even, and if I go with a monitor upgrade a gpu upgrade to 1 gb would be smart. For that case I was thinking of getting the following;

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5250626&sku=E145-0257

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5571783&sku=A466-2304

Are their any better options to upgrade my computer? Thanks in advance!

Get a 460 and a quad core if you mobo supports it. Oh and install 64 bit windows so you can use that 4th gb of ram.