An eyeball look at some airplanes designed for RC aerobatics can be seen here -

http://www.rcuniverse.com/showthread...82&forumid=232

and

http://www.rcuniverse.com/showthread...44&forumid=232

and

http://www.rcuniverse.com/showthread...71&forumid=232

Compare them to the standard F3A airplane and you find the wings are a little smaller, thinner and there are two of them on the same fuselage. The same aspect ratios, etc are there.

Dihedral on a bipe works the same as dihedral on a monoplane. The presence of the upper wing causes a dihedral effect and putting anhedral into the upper wing has been done. It looks funny so most designers don't do it. The engine for total wing area requirements are about the same I think. Considering the range of engines that are put on standard monoplanes (depending on the use of the airplane) the engines used on bipes are not all that much different.

I do know some of the visitors to this forum have had experience designing bipes so they should give some input..