Question about Video Card for SC2 and Mobo

I have an old video card and wanted to update to support Starcraft 2. I watch TV shows and movies on my PC sometimes, but don't typically do anything graphic intensive. I don't play other games on my PC so I'm just looking for something that will play SC2 that is compatible with my motherboard. I have an Abit IP 35 pro. Looking at some cards online, some say 2 x 16 PCI-E. Looking at the picture of the abit ip 35 pro, I can't tell if my Mobo supports these types of cards. Does anyone know? I wasn't sure if I needed a different Mobo for those cards. Or should I be looking for a 1x16 PCI-E video card? Also, I don't know if it's possible since video cards do alot of processing, especially for intense games, but I'd rather have a card that would be more quiet, or at least quiet when I'm just surfing the web and not playing Starcraft 2. Thanks!