I have a "problem" and I'm seeking a solution. Here we go:
I recently bought a GMP 1/3 scale Laird Super Solution Biplane. It has the following:

Span - 76" (top wing)
Area - 1633 sq in
Wing loading - 24 oz / sq in
Length - 60"
Weight - 17lbs
Engine - 50-80cc

Previous owner used a G-62. Here's my "problem" I have a 3W 60, a Sachs 4.2 , and a Z-445 twin. All fit the firewall and the cowl (12 1/2" round, 8" deep). Which one would you use and why? Thanks in advance.