I think what Meloco is saying is, if you've got that much money to spend if you can hold onto it for a month you'll probably find a better buy or a bigger range. I think its the new intel chips coming out (someone correct me?)
When I asked why you were choosing he Q9550 i wasn't expecting you to get a more expensive one, but more wondering why you wanted that over say the Q6600. OK so its getting a little old now, but it overclocks without any effort to 3.0Ghz and memory still on 800MHz. I've just been playing Crysis warhead on mine with my 8800GTX and looks fantastic.
If you're wanting to play on a 24" then the GTX280 is a good call, anything lower then I would look at the HD4870's or even the HS4870x2's (that would be great on a 24" ) though there is a lot of talk about the noise and temps. And well if its crysis/farcry you'll be playing I'd stick with the GTX280's
Corsair HX620 would be perfect for what you want, my only quibble would be the price... 0_o it seems to have gone up again!
Asus P45Q would be my suggestion for your board, though it wouldn't give you room to put another gfx in as well later if that is what you are thinking of doing, though a GTX280 is more than enough for most people.
I'd stick to the Q6600 and put my money somewhere else, but I'm sure people will tell me I'm wrong. Throw in 2x2GB DDR800 OCZ reapers and your away
As for case if you like things plane and quiet look at the P182 otherwise Coolermaster have got there new case out which might be worth a look: HAF 932 ( no idea how good it is, but looks the part)
