Wow....I LOVE the GeeBee....I want a GeeBee Z so bad I can taste it. I know how you feel, nunnoahrun, I dont' like to wait to get to the planes I want to fly either. There are some great suggestions here on how to progress. In my case I saw a used "Ike" which is the same era of the GeeBee and a racer from the '30s, I had one of our experienced flyers at my local club take it up. The flight was hair raising to say the least, he managed to get the plane down in one piece, but threw his hands up and said "i'm done with that!", talking to him further, he said that the faster it went the better it flew, but, it flew like a brick and was extremely difficult to land. So, I put that bird away for a while and it's a great conversation piece(I sometimes bring it to the field and set it up) it gets a LOT of attention at our field. It's my "goal" for when I get to be a better flyer.
I'd say buy it, build it, bring it to the field and set it up......but don't fly it. I don't know what kind of plane to recommend to you to fly to simulate the GeeBee, but listen to some of the folks here, and make your own decision(because you will anyway). I went from a trainer to a "sport" warbird and the thing that threw me was the speed difference(take off and landing), the more sensitive controls and a number of techniques for just the basics of flying a taildragger that you really don't appreciate till you actually try it. If you haven't flown a low wing taildragger yet, do it....I think that will tell you where you are with your flying skill and will definitely give you a wake-up call, it did for me.
Good Luck!
Cheers!
Mazer