Your engine and radio equipment can be transferred to almost any 40 size ARF that requires a 4 channel radio.

I'd get another trainer and practice landings before moving up to a plane like a Funtana. The Funtana is built extremely light compared to most trainer planes. Rough landings will destroy it. There are dozens of good flying, fairly tough, trainers available

Trainers with flat bottom wing:
Hangar 9 Alpha 40
Hobbico Superstar 40
Tower Trainer 40
Sig LT-40
Thunder Tiger Trainer


For a semi-symmetrical wing (slightly more aerobatic) but still a trainer:
Hangar 9 Arrow
Hobbico Avistar
Thunder Tiger Trainer