I'm 5'3" and I love my 49cm Specialized TriCross. I bought the TriCross in order to do the same sort of riding you described, but I've ended up branching out with it to do more road riding and a litte mtb. It's terrifically versatile. I tweaked the fit a bit as far as the stem/bars, but the frame size has been just fine. Sorry I can't post a link to info about it, but I'm at work and snuck on-line for a few minutes