The Hog bipe and the Tigermoth as mentioned are well behaved aircraft that you should have little problem with.

The biggest difference with a biplane is increased lift/drag. They slow down real fast. When landing, keep a little throttle on until you're ready to flare, you have to fly them all the way to the ground, if you chop throttle and glide like you do on the average trainer, you'll be in for the walk of shame.

Another important point. If you end up dead-sticking, don't expect a long glide. A straight ahead landing off-field will most often result in less damage than a turn back to the field.

Whatever you decide, enjoy, there's nothing prettier than a bipe in flight....