Re: Suggestions for MFA portfolio in painting
Most schools list their requirements on their website, and provide contact info for a graduate advisor. The Grad Advisor is your friend ... I recommend confirming (by phone or email with the advisor) what their portfolio requirements are (types of work, preference for digital or slide, forms to fill out). Sometimes the websites are out of date. No point spending $$ on slides, if they prefer digital!
Each school may have slightly different work they'd like to see. From my limited West Coast school research, many want to see a focused body of work that demonstrates the ideas from artist's statement. Not sure when you got your undergrad, but its not bad to spend a year or so painting to build up new work your are really proud of - might also help you decide where you'd like to study.
If you still have contact with your undergrad program, show them the slides of work you want to include in your portfolio to get some feedback.