If you are going with the WM, I would go with the standard. My avatar is a WM .26 Cub with an O.S. 30 fourstroker and robart scale wheels. If I were you, and not on say a tight budget, I'd spring for a Saito twin. I am trying to get my hands on one now but it looks like it won't be until christmas before I get it. I will be getting the Saito 100 Twin from Horizon and putting it into my .40 Cub. It will be way too heavy by R/C cub standards but should still be much better than scale. Otherwise any 50+ for scale and 70+ for standard R/C performance. Mine flew quite scale on a 10 x 6 master airscrew. If I were to rebuild it, I would choose the 40 because with the cubs, a little power on tap for those rare occasions when you botch a turn is always nice.

There's nothing so beautiful as the yellow Cub flying in the sky. It is flight in a most pure form.