The gasoline engine is certainly a good option as the fuel would be lower in cost. But the problem is typically the noise levels the gasoline engines produce. The engines typically have really crappy mufflers on them, that do nothing to reduce the noise levels. So the engines wind up be noisy and very annoying in some locales. But it depends on where you fly too. if you have residential housing nearby, you may be more restricted then because of the noise levels. it does help a lot to go with a canister muffler system, but these are more expensive, larger and harder to place inside the airplane or something.

The Saito would sound a lot better though. The 4 stroke engines aren't as annoying as a gasoline engine with a crummy muffler on it.