All the cards will without any problems will handle two monitors. As for draw backs of having a card without fan: You need to clean the dust out of it every 2 months, or it will start overheating. And yes, it's possible to upgrade more.
Power supply unit: Corsair CX 500
Graphics card: Gigabyte Radeon HD 7870
To be honest, it all depends on your budget, and if you don't want to spend that much - the first card recommended will work without any problems as well! Though, of course, HD 7870 will play games on higher settings/with more frames per second
. It's twice as fast.