Originally learned tailwheel flying in a Citabria 7ECA. Very docile and fun to fly! About two years later I bought my first airplane which also happened to be a '65 7ECA. I had a lot of fun with that airplane. Right before I purchased, I had it narrowed down to two airplanes. Both were great inside/out and priced about the same (approx $27k). One had the 150hp conversion and bare-bones VFR, the other had an O-200 with (believe it or not) an IFR panel! I got the one with the panel thinking it would be convenient to get out of the clag if you had to. I think I flew in IMC twice (once to be stupid, twice to make sure I was being stupid). Don't get me wrong, I loved that airplane. It was great, but looking back, I'm sure I would have gotten a lot more use out of the extra 50 horses.
Maintenance was easy on this airplane also. I learned a lot about part 43 and owner conducted preventative maintenance. Plus, when you own a classic little airplane like this, A&P's WANT to help you out. Just because it is something different. When it comes to Citabria's, I would look for a good wood spar aircraft (spelled, hangared). I believe that there may be some ADs on the metal spar. Either way, check into this CAREFULLY.
Also keep in mind that any fabric airplane needs to be hangared. This can become a stumbling block unless you have something lined up or happen to live next to 2000' of grass with your own hangar. I got away with leaving my Citabria outside for 2 years, but only because 1) I had a cover, 2) I wasn't married, 3) I could afford the time to wash it every week and wax it every other week. (This helped keep UV damage to a minimum) If this could be a problem for you, I would go with a Luscombe or a 140.
I've upgraded to an aerobatic biplane now. Not nearly as docile as the Citabria, insurance is much higher and my wife hates it. But that doesn't matter, because it is an ABSOLUTE BLAST to fly. (apparently her requirements for a nice airplane are: a roof and luggage space. Weird.)
Good luck with whatever you decide. Remember, it's not hard to own an aircraft. You just have to make up your mind that you WANT to be poor....