Should I apply MD or MD PhD?

I hope this is the right place for this post, if not, I'd love direction elsewhere. Research is very important to me and even if I just pursue an MD, I would like to take a fifth year and do a post doc after residency (or during depending on the specialty I choose). But an MD PhD may be a better option for me application-wise, it is not my first choice as I'm concerned about my education taking too long (4-7 year PhD length is what's killing me). So I'm hoping for some feedback on if I... Should I apply MD or MD PhD?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Tags: What Are My Chances? WAMC Medical Source Type: forums