Well........... I met a guy on the scale aerobatics forum and he was using a zenoah 64. he was tail touching it. Spose the fuji would be better but theres the factor of weight, both theese engines are heavily modified chainsaw and lawnmower engines which are real weighty. I would pay more, buy a lighter engine with more power. i always say if going to do it, do it properly.
Hope this helps (proberbly not )

Ian