Yet another gaming build - thoughts?

Hi all,

Normally I'm not one to post a thread like this, but haven't really been following the hardware market for the last few years, so I've kinda lost track of what's out there. My old P4 recently died and so I need to build a new system. This is what I have to work with (useful components salvaged from the old machine excluding storage and whatnot):

Case: Antec 900

PSU: Antec TruPower 550w

Vid: ATi x600 Pro

What I'd like to do is get this machine running again in a minimal fashion, then go from there. What I was considering purchasing immediately follows:

CPU: Q6600 - $240 AUD
http://beecom.com.au/product.php?p [...] 289&page=1

Mobo: Gigabyte X48 DS4 - $275 AUD
http://beecom.com.au/product.php?p [...] 306&page=2

RAM: 4GB (2x2GB) Corsair DDR2 800 - $130 AUD
http://beecom.com.au/product.php?p [...] 389&page=1

Eventually (within a week or two) I'll replace the x600 with:
Vid: Sapphire 4870 - $319 AUD
http://www.onlinecomputer.com.au/p [...] e9db828d9b

I'll be using this machine for a bit of everything, and it will have to last me quite a while. I was planning on waiting for Nehalem, but alas, motherboard failure waits for nobody. The most stressful things it will do is run Supreme Commander and Warhammer Online (both of which are multithreaded, iirc - hence choosing the Q6600 over the E8500). Eventually, I plan on crossfiring with a second 4870.

Cost is an extremely limiting factor right now (hence the gradual replacement of non-critical components), so I'm open to suggestions (particular with regard to the motherboard).

I'm hoping the 550w Antec PSU will be sufficient until I get a second card.

The case might be a little tight inside, but theoretically it should all fit. I'll also grab a decent CPU cooler when I get the CPU.

You guys must get so sick of seeing threads like this, but I'd appreciate any advice from those more in the know than I.

TIA.

EDIT: Oh, and I intend on overclocking the machine.

^ agreed, great mobo, adequate PSU, good RAM, good CPU when OCed.

He's not paying, he's just going to use the salvaged one for a while until he gets the second card. Later on for dual 4870's, the Corsair TX650 would do the job.