Jim,
I like your engine choice too, and the weight should not be an issue considering how tail-heavy the airframe tends to be. I suspect you are going to run into prop diameter limit pretty quickly. I ran a Quadra 42 on mine that could handle a 20x8 (more often an 18x10). I found that the 20" prop would kiss the ground at unexpected times. Yeah, I know, my flying is suspect. Be careful nonetheless.
Have fun!
Bedford