Keith...
If you intend to use an engine in the planes that you intended for a FOX .35, then I would suggest a Brodak .40....it runs well, has plenty of power and there is a lot of help regarding props, fuel, etc...
If you are looking at somethin with more power, I would suggest the OS LA .46....
Remember that the .40 is considered safe on .015" lines, while the .46 wants .018"
Have fun!