Pedro,
Were (what club) do you fly?
What is your interest? Scale, Fun Flying, Easy build, ????
There are so many great bipes for different reasons.

Super Sky bolt as Deadeye has mentioned.
Sig- Smith Miniplane 43inch (or so) wing really fun flying airplane.
Balsa USA- EAA Bipe 60inch wing good intro to bigger kits.
If your wanting full blown aerobatics just about any of the Ultimates.

If you can find a old Great Planes Super Sportster Bipe, they are easy and fun. They clasify for a bipe since they do have two wings.