25 is still quite a big thing in the UK, lots of plans about, try www.rcstore.com for some plans other side of the pond.
if you got the skills put that 25FX in a 15 size shrike and hold on.
any Cambrian Funfighter will be good with both engines, i've had the spit and mustang, flown the others, the mustangs best, the rad is good for low passes and not cutting the engine
lots of the Comp style funflys, Stick-it ect will be good on a 25 FX.
Build a PBF ( fun fly forum ) and put the FP in it, LOTS of fun