The mounting points should be standard - smaller boards you won't have a problem with - the issue comes if you have a full form factor board, and it simply not being able to fit - that's obviously going to be an issue. If the board is a standard ATX or Micro-ATX form factor (which almost all are), then the mount points are in the same area. If it fits inside the case, it will work.
For the power supply, yes. Corsair makes decent stuff. But if you're going for a high end graphics card, you'll want to look at higher wattage - you can check the manufacturers website for recommended ratings - and add 100W to that at a minimum for growth/load. If you're going to be running a lower/mid level card, that should be fine - I personally would look towards 500-600w range with modular cables.