Can I use a 200amp panel on a 100amp service / Is their a small 200 amp panel?

So I have a 100amp service to a small area above a garage. The panel is located in a kitchen cabinet and is being moved to an interior wall. I have a service disconnect/breaker being installed next week so the panel inside will become a sub-panel. Here's that thread on the disconnect though it's pretty unrelated to this question. http://www.diychatroom.com/f18/how-long-add-service-disconnect-350178/index2/

Anyway, I'm going to leave it as a 100amp service for now which I think will be fine. I want to use a 200 amp panel inside and run the feeds in 2" conduit. This way if I need to upgrade the service later I don't have to rip open walls and ceilings. The only inside work would connecting the new wires to the panel. The panel is protected by the 100 amp breaker feeding it so that will prevent the wires feeding it from overloading. Is it okay to use a 200 amp panel with a 200amp main breaker in this scenario? This is what will be outside. www.homedepot.com/p/Square-D-by-Sch...0;jsessionid=F8DA23BCB7DB5A6913D58A7C76F9131A

2nd question. If I can do that, do they make a dimensionaly small 200 amp load center? I only need a 20 space or so panel. Every 200 amp one I see if pretty close in size. Some have smaller buses but the panel itself is the same size.