I'm looking to catch the room sound of two guitars, bass and drums, and vocals. Right now I have nothing but a new laptop with vista. The interface I am considering is the Presonus Firestudio. The room size is 15' X 20'. I was thinking of two area mics but I'm not sure which to go with. Do I need a pre-amp? I want to eventually build a full studio, but I thought I would start this way so I could record the band. Any thoughts?