I am building one now. What I will be using is the OS 120 4 stroke. The 4 stroke is out of my price range also, new that is, I bought the OS here on RCU as a used motor about a year ago and got a great deal on it. The motor has run perfectly. And I didn't have to bother with the break in process.

So far I have taken advantage of 3 used motors here on RCU, I have been happy with all of them.

I have seen this airplane fly with a Super Tiger 90 2 stoke. Great motor with more than enough power.

hope this helps.

tonyc