I'm thinking of getting a new computer cause my current one is crappy. Can't even play Counter Strike without lagging in 10-player server.
My computer guy said he'll make me a good computer with 7300(and 2 giga and all that good crap) for 800 bucks. However he said he can also give me 7900 and 2-3 gigabyte(Depending on mood) for 1,000+
GeForce 7900 Series is lot more faster then GeForce 7300 Series. The reason is that GeForce 7900 Series is for designed for "enthusiast" gaming experience.
Regarding RAM:
And 2 GB RAM is more then enough for current gaming and computing needs. Get two 1 GB RAM Sticks and make a "Dual Channel Memory" Setup.
3 GB RAM is not necessary but the choice is yours.