Time for a new CPU?

I just received and installed my new MSI 6600GT-VTD128SP vid card to replace my old 128MB MSI Geforce 4 Ti4200 card, but I have a few questions.

My CPU is pretty old, its a P4 2.00GHz, socket 478 (flame at will plz), and after running 3DMark 03 and comparing my scores with the 4200 vs the 6600GT, I think my CPU might be the factor holding me back, since my scores are much lower than on many benchmarking sites.

Here are my 3Dmark 03 scores, both cards aren't overclocked:

1028x768, no AA, no AF
Ti4200: 1433
6600GT: 6974

1028x768, 4xAA, 8xAF
Ti4200: 508
6600GT: 3971

Now even if I did upgrade my CPU, would it really make much of a difference on BF2 and F.E.A.R., which is what I mainly bought the card for? I'm looking for a CPU around the 3.2~3.4 GHz range... I want it to be decent, but I don't want it to be really expensive and produce a ton of heat. Nothing uber-fast here ^^. I might be leaning toward AMD, only if it will be compatible with the rest of my comp though. Any Ideas?

My PC specs for reference:
Lian Li PC-60 case
Enermax 535W PSU
Intel P4 2.0Ghz
Gigabyte GA-8IEX mobo
2x 512MB Kingston PC2100 DDR SDRAM
6x IDE HDDs, ranging in size from 80GB~300GB
crappy DVD/RW drive
128MB MSI 6600GT
Soundblaster live 5.1

the formatting of my posts has been weird lately, so sorry if all the words turn out mashed together with no spaces :/

>>4
I have to use the shitty bargain bin ram because my MOBO can't handle better than PC2100.

I will most likely do a complete overhaul this upcoming christmas with a new MOBO, ram, soundcard, and CPU.... but even if i were to replace all these components, what CPU should I get that meets the requirements i stated above? (good, but not too expensive, and produces low heat)