Looking to upgrade video card from Geforce7300. I have a micro case and need good ventilation. Suggestions?

I have an Nvidia Geforce 7300, 256mb etc. I'm looking to upgrade it so I can dual-client some older games without lag. My computer is small, I have a micro case, so it *needs* to be well ventilated and not huge. Any suggestions?|||need to use a case fan if possible