jake - almost all planes are suitable for conversion. The issue is always getting the batteries at the right place for the correct CG and access to the batts. You want something that will turn a minimum of a 14x10 or 15x10 prop giving you about say 700-800 watts. You can run a 4S or 5S (3,700 to 4,500 mAh packs) set up with an ESC rated at 60A/80A and 6S. If you want to shop cheap then go to United Hobbies.

One word of warning ... warbirds like to come in faster, much faster than your trainer. If not it will stall and drop out of the sky. Just be sure that you really are ready for the plane. Also, the mess is not that bad as EP is not cheap and it will be hard, not to forget expensive, for you to try and get 15 min flights. You are looking at 8-10 mins max. Why not get the plane with a nice Saito 82, even a simple 70-80 sized 4C will fly her fine and its much cheaper than EP (you need multipe packs to fly a lot and also don't forget the charger and balancer).