The 10cc class gas would do it I think. The problem is the 10cc class is so new you're going to have a tough time finding others running them in 3D or even performance applications. I have a 10cc Evo on this plane:

http://www.generalhobby.com/skyline-...een-p-359.html

At 5lbs. w/650 sq in of wing area, it's an outstanding performer, but I haven't spent the time required to get it into 3D trim yet.

Point being, the Saber is lighter yet, with more wing area - both bonuses when considering 3D aspects. In glow form, and electric, this plane has a pretty good reputation. Though I haven't done it myself (yet?), it's on the short list as I'm pretty sure the plane has potential.

In addition to the ignition type gas engines, there are also those engines using glow plugs in place of the ignitions. The feedback on these are mixed, so hesitant to to suggest/recommend. The NGH 9 is in this class, but they have issues. Suggest you not consider one.

Evo, RCGF and OS are the ones to pick from.