I say if you have the money,gas is the way to go.There are some really nice small gas engines available now.I really like my 3W24 alot.A little cheaper is the OS 160,but you'll have to put a pump on it to get it to run right.That motor will fly the crap out of that plane.If you want to go 4 stroke,my suggestion would be a Saito 150 or 180,or a YS for more money.
I have seen thet plane and it is very nice.I like the airfoil tail on it.Wish mine had it.
Good luck with your decision.It's going to be a tough one.

Hank

PS: Just some food for thought.Gas is a little more expensive in the begining,but actually cheaper in the long run.$1.50 a gallon plus $2 for oil vs. $10 for nitro.