I owned a Citabria for about four years. Best fun I've ever had in an airplane. PM me if you have specific questions.
It's not really underpowered for what you want to do, which is do a couple of basic inside manuevers and then climb back up to a minimum altitude of about 5000 AG. Even with a climb prop, it will take a while. Which is WHAT YOU WANT, it's easier on the upholstery.
I had 150 HP version which had an alarming climb rate, especially in the wintertime. Like 1200 FPM off the deck with a serious body angle. Loved it. The O-200 version was fine too.
Don't believe the doomsayers who say tailwheel is hard to fly. Like Joe says, it makes you a better pilot. After about a decade of flying Wichita Flak with a nosewheel, I finally learned what directional control was all about. Tailwheel aircraft, whatever type, are unforgiving of sloppiness, that's for sure.