Well, for what it might be worth, here's the mSATA adapter, beside the mSATA drive I use with it. This combination works beautifully, and is nice and compact. It also has the benefit that mSATA drives are only just coming into fashion and should be commonplace and useful for a few years yet.

When purchasing one, ensure it has the 3.3V regulator populated (black thing, near bottom), otherwise it may fry the mSATA drive.