Start in a riverrunner with creeking potential. While I normally yell PLAYBOAT! every chance I get, you will be happiest in your area in something else.
Liquidlogic Remix is a personal favourite in the "River Runners that Creek" category, as well as the Pyranha Burn. Many folks like the Dagger Mamba, but I honestly haven't spent much time in one.
I would also suggest going size Small. I'm about 10lbs heavier than you, and I paddle medium boats only because I am 5'11"--I don't fit in Small boats. You'd fit them really well!
I believe you will have more fun learning in a smaller boat type than a creeker, and you will learn more effectively. Anyone can go from a playboat to a river runner to a creekboat--upsizing is easy. But you will limit your learning if you start in the easiest boat.
LL Remix 59
Pyranha Burn (Small)
Dagger Mamba 8.1 (maybe)
Have fun, be safe, and practice lots!