Need Help on finding a case.

I Need help finding a case and Power supply combo.

I have this mother board

http://support.gateway.com/s/MOTHERBD/MSI/106623/106623nv.shtml

Iam wanting a new case and power supply but i want to be able to upgrade the mother board later on. Iam on a fixed income and iam wanting to upgrade piece by piece.

My problem is when i look at the back of my pc the mother board is on the right side. Normally i see the mother boards of the left side of the case. Which is were my problem lays.

The computer i have is

Gateway GT5062E Desktop Computer

I want a case were i can upgrade the mother board later down the road that way i can have sli and up to 8 gig of memory.

Any help would be apreciated.
shawn