I'm planning to apply to business schools within the next year or so, but wanted to get a sense for how my GPA is going to hurt my chances and what I can do to counter that impact. I'd only really go to business school if I can go to one of: Berkeley, H/S/W, Northwestern, Dartmouth, MIT.

GPA (top LAC) - 3.5 overall, history major. My math/sciences GPA is lower, closer to 3.1
GMAT - 760
Work experience summary - 1.5 years investment banking top firm (nyc), 4 years PE at well-respected/unique entrepreneurial firm with a lot of internal leadership opportunities (not nyc).
Outside of work - Founder of non-profit charitable organization providing sponsorships (funds/gear) to underprivileged extreme sports athletes around the world (surfers, bikers, skaters, etc.). I'm a sponsored mountain biker/skier.
Goal of MBA - Been offered partner track at firm, but want to use MBA to raise a search fund to buy/run a company after graduating. Use that to create track record to found an investment firm.
Recommendations - will be extremely strong from partners at my firm
Native american background - not an official tribal member, but it's part of my family's cultural heritage and my identity.

What should I do to counter my low GPA? Would it be worthwhile to take a business-related course or two at a local college and ace it?

Thanks for the input.