I'd love to upgrade my video card, but I couldn't find a decent card to replace my 8800 GTS and I can't do SLI because I only have 1 PCI Express x16 slot... So to upgrade my video card, I need a new mother board. I have found the one I want:
GIGABYTE GA-EP45-UD3P LGA 775 Intel P45 ATX http://www.newegg.com/Product/Product.aspx?Item=N82E168...
I'd like to keep my current CPU (I can overclock it fairly easily), but on the Gigabyte site it says that it does not support the Allendale core, but it DOES support the Conroe Core. Both of these are Core 2 Duo E4300, 1.8 ghz, 800 mhz FSB, L2 cache, 65w, and 65 nm... so can my proposed new mother board support my old CPU? If it doesn't support my old CPU is this a good replacement?:
Intel Core 2 Duo E8500 Wolfdale 3.16GHz 6MB L2 Cache LGA 775 65W http://www.newegg.com/Product/Product.aspx?Item=N82E168...
8800gts-320 to 9800gt-1024 does not seem like that much of an upgrade; they're both of the same generation, though the latter is at a better process node.
What exactly are you trying to play; what resolution/settings?
For less than the price listed in your link, I think HD4850 is a better deal.
Without replacing your motherboard (just your PSU, perhaps), you could fit a 9800gx2 or even a 4870x2 in that lone PCI-e slot. The second option approximates SLI'ed GTX260s... price and heat output are commensurate. Your motherboard still leaves you many expansion options; if it's working fine, no need to toss it.