There is a thread at rcgroups.com on a nice Tiger Moth wood kit from Balsa Products. That guy is using electric power, and I don't know if it's sized for the .30 4stroke but it looked like a good kit of the lovely Tiger Moth.
Also, in that size it wouldn't be that much harder to build from plans, which would open a large source of good airplanes.
Most of the magazines carry an archive of plans with the accompanying construction article.