RE: Which one makes a good first biplane and why
A first bipe? I think it really depends on how well you fly. I had an Ultimate 30 from World Models that I absolutely loved as my first bipe. With the small wingspan and fuse length, it could fit in the car (Toyota Supra) fully assemblied. Anyway, the point is that if you are a capable pilot with lots of flights under your belt with highly aerobatic planes, there's no reason why you would need to go with a mild bipe like a tiger moth unless you like the looks and the mild flying characteristics.
If you can fly a low wing trainer - Tiger Moth
If you can fly a aerobatics on a low wing plane (like four*) - Sig Hog Bipe, Super Stearman
If you can fly pattern (f3A), 3D - Ultimate
By the way, make sure you get someone that knows bipes to check the CG and setup out before you fly. And I would definitely recommend you let an expert take the plane up for its maiden. Bipes are not easy to set up and often aren't as friendly when they aren't.
Also, orientation isn't so easy so make sure you have a spotter and don't fly too far the first time.
So you figure it out. And be honest... because even an honest mistake is hard to repair!