I really like adaptable flanker, it lets the roge sneak attack from a much safer place, while the fighter is tide of ironing himself to the thick of things. Tumble can put you in a bad spot if you're not careful, of course it can also get you out of a bad spot too. I'd definitely go with one of these though, so you have some early combat sneak attack options before the rest of your party can open up the field for you.