Here's a thought. Take a Skybolt and increase the span to between 65 and 70 inches. Square the wingtips to assist the roll rate. Increase the depth of the ailerons and bring them into the fuselage sides to increase the high angle of attack effectiveness. Also double bevel them for more range of motion. Reduce the size of the horizontal stab by increasing the size of the elevators and add a double bevel. Slightly increase the height of the vertical stab while increasing the depth of the rudder marginally. Again, add double beveling. Use the method of "I" strut attachment that was used on the Great Planes Skybolt.

Darn, this is sounding good enough that I might drag out an old kit I have in the shed to try out the fuselage changes. I would have to get another set of wings, though. Used them on another Skybolt.

Another great flying bipe is an Ultimate Pitts. Properly set up and designed, it will outfly both the Pitts and the Ultimate. Just ask Sean Tucker and Jim Leroy. You could always bring back the Weeks Solution with a few modifications for 3D. If you can't already tell, I have a love affair with aerobatic biplanes.