Every choice you make in life opens some doors and may inadvertently close others. At this point in history, if you're an MD from a reasonably good medical school, and you do well on the GMAT, you should be able to get a spot in a top business school (that may change a bit soon). So my question is, with tuition costs about the same across MBA programs, why wouldn't you go to a top MBA program? Several of the top programs (namely Kellogg, Wharton, Chicago) have excellent part-time programs that would allow you to practice and actually earn (and save) money while you are doing the MBA. These can be done in 2.5-3 years. As a doctor, you can work anywhere in the country you want, so why close doors? Even if you don't want a "traditional" corporate job, you never know what opportunities might arise.
I would also be cautious about pursuing "executive MBAs" or "healthcare MBAs" even at top programs. You might learn a thing or two, but they really are expensive, and of somewhat limited value if you do choose a traditional route unless you already are working for a company where you want to stay.
Finally, I think with the current turn of events in the economy, the days of physicians doing APD programs at McKinsey or BCG and then just waltzing into private equity firms are pretty much over. You'll probably need an MBA from a top program to get hired by these firms with the stiff competition from job seekers for the next few years, so go big if you know what I'm saying.