Minimalist Upgrade

Looking for advice on an upgrade of a ~ 5 yr old rig I built. I have a self imposed limit of $350 and want to find the best GPU/RAM/Mobo/CPU combo. I am not a major gamer, but want to play two games I just got (Halflife 2 and Bioshock) as gifts at reasonable settings. I am hoping my Antec 430W PSU will suffice but will upgrade that only if absolutely required and not included in the $350 limit.

GPU:
$115 US (all prices are from Newegg and include shipping)
SAPPHIRE 100218L Radeon HD 2600XT 512MB 128-bit GDDR3 PCI Express x16 HDCP Ready CrossFire Supported Video Card - Retail

CPU:
$85 US
AMD Athlon 64 X2 4800+ Brisbane 2.5GHz Socket AM2 65W Dual-Core Processor Model ADO4800DDBOX - Retail

MOBO:
$85 US
GIGABYTE GA-M61P-S3 AM2 NVIDIA GeForce 6100 ATX AMD Motherboard - Retail

RAM:
$65 US
CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail

Going over the $350 limit is not an option, but other combinations within the price limit would be fine. One other dumb question: How big a deal is it if my harddrive isn't SATA? I can get a new one, but it would have to come within the $350 and drive down the specs of my other components. I was hoping to keep my current hard drive for now and upgrade it to SATA in 6-12 months.

Thanks in advance for your help.

Well there's this ram I was going to get it's a little cheaper.

G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL5D-2GBNQ - Retail

I might look into the gpu a little, and I don't know anything about mobos yet but I'm learning. Also I would probobly get a slower cpu but overclock if that's an option you could overclock it faster than it the same or whatever.

There won't be too much of a difference between SATA and IDE hard-drives, or at least not enough to replace a perfectly working drive.

Or at least that's in my opinion.

Thanks for the suggestions. I may try to wait a month or two and let prices drop on the Radeon3850.

I am wondering for my $350 limit upgrade what can of performance I can expect with the configuration below or should I skimp on the CPU/Ram/Mobo to saveenough for a3850. Would that system perform well in gameslike HL2 and Bioshock or would the GPU be bottlenecked by the other hardware?

Thanks forany input.

GPU $115 Saphire Radeon HD2600XT 512 MB GDDR3

CPU $85 Athlon 64 X2

RAM $65 2GB DDR800

Mobo $85 Gigabyte GA-M61P-S3 AM2 Nvidia