The HD4870 is the fastest of those three.
I'd recommend a larger hard drive. 500GB - 750GB are quite cheap nowadays. 160GB might not be enough with a bunch of games installed and iso's. Also, you're going to want DDR2 800 (PC6400) RAM as that motherboard supports DDR2 and not DDR3. Don't wait too long on getting 4GB+ total because manufacturers are cutting back on production for DDR2 since DDR3 is the new standard. Prices will get pretty high like they did with DDR.
Big question. What power supply are you planning on buying? You don't want a low-quality one that's more likely to die early and possibly fry some other components with it.
I'd recommend a larger hard drive. 500GB - 750GB are quite cheap nowadays. 160GB might not be enough with a bunch of games installed and iso's. Also, you're going to want DDR2 800 (PC6400) RAM as that motherboard supports DDR2 and not DDR3. Don't wait too long on getting 4GB+ total because manufacturers are cutting back on production for DDR2 since DDR3 is the new standard. Prices will get pretty high like they did with DDR.
Big question. What power supply are you planning on buying? You don't want a low-quality one that's more likely to die early and possibly fry some other components with it.