Another big Martin fan here so you made an excellent choice!
After playing every guitar in the shop I went for an OMC 16RE Aura, which fitted my needs perfectly
If you are going from an electric to an acoustic I highly recommend that you check out the DR Sunbeam strings
These are wound on a round core (rather than the normal hex core for acoustic strings) which makes them a little easier to play (especially string bending) WITHOUT compromising tone
I tried loads of different types when I first got my acoustic and I now don't use anything else!
I also recommend using "stringbusters" for buying strings - great service, excellent pricing and quick delivery!!!