The two planes are worth whatever you can get for them as sport planes. As combat planes, neither is really going to be competitive or a very good plane to have at a contest, so I don't think you'll get many takers.

For the biplane question, you might try the scale or warbirds forums. There are guys flying profile WWI combat, as you noted. You could always take one of those kits and use the side view to build out your own fuse to go with it.