I would definitely suggest you get some another 2GB ram to go with that and then also get a better power supply. As specially if you only have 350W. Generally, you can get away with thinner and less power consuming cards, but this is sometimes a bit slower.
What's your budget like on the card? If you can, try and get yourself a Geforce GTX 650TI 2GB card, that should hold you over for a while. If you can go higher than these prices, generally around R2500($220) then you've got some really good specs to go for.