Nathaniel,
I did pretty much what you are planning on doing. After I soloed with a Hobbico Superstar trainer RTF, I started building the Top-Flite P-51D Mustang, .60 size. I like to build things, so the thought of building a warbird for my first kit didn't scare me. It took me about 9 months to complete it, working on and off. It was a blast to build. I learned alot about what goes into make a strong, straight, flyable plane.

I had a member at my club, that I consider a great pilot, perform the maiden flight. I've flown it a couple of times by myself (just to say that I had). I'm now finishing up a four star 60 kit as my next daily flyer. Everyone tells me that the fourstar is great second plane.

If you really like building then I recommend any of the Top-Flite kits. The warbirds were alot of work, but the instructions were very easy to understand. If you're not sure wether you'll like building a warbird kit, then I recommend the SIG fourstar kit. It is WAY simpler to assemble than a warbird, and if you enjoyed it - then you start building your warbird.

I hope this rambling helped some...