Upgrading Video Card

[patio]

This would be entirely based on the budget wouldn't it ? ?
It doesn't matter how long it takes.

[Gamecheater]

Well, I have picked out the parts for my new computer. Just wanted to see if all of this is compatible...
Motherboard -
http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=3523225&body=MAIN#detailspecs
Processor -
http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=2905631
Case and PSU
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3523889&Sku=TC3J-2335
Hard Drive -
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3405853&CatId=139
Video Card -
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3538922&CatId=1826
RAM X4 -
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=2205992&CatId=2033
DVD Drive -
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3032692&CatId=89

Hopefully all of these components will not overheat ^_^

Another question, woud it be better to get a Nvidia video card for this setup or a Radeon? I want the maximum performance, and I have heard great things about Nvidia.

[homer]

that is a SLI motherboard. SLI belongs to Nvidia, so its best if you purchase a Nvidia card. you can still purchase an ATI card, but you will not be able to use Crossfire.

why, under the link you gave for RAM, does it show an 8800GTS?

[Gamecheater]

Sorry, must've screwed that up. Fixed now.
IS all of that compatible? Would it overheat?

[homer]

that is all compatible, however, you may wish to purchase your RAM in pairs, it might be cheaper getting 2 sets of 2 sticks then 4 sets of 1 stick.

Would it overheat?

that depends solely on overclocking. if you wish to run all your components at stock speeds, then they will not overheat.