I've tried Cox 1/2A powered bipes a time or two, and overall, they weren't really a success. Too much drag, I think, is the trouble.

How about going over to the Aeromanics site:
http://www.aeromaniacs.com/ and doing a platter to get your feet wet. Larger CL models can actually be easier to fly than the little ones, much as I like the Cox and Norvel motors.

There are a ton of easy designs out there for 1/2A, some free, many for just a few bucks. Flying Models plans service probably has the most. And ask over at the Stuka Stunt Works forum. I bet the guys over there will help you out. I have plans for the Baby Flite Streak I'll send you if you want them.
Kelvin