A lot depends on your budget, prices vary and the quality reflects this. hmm heres my suggestion then. Id go with a 700 size motor, spinning a 40 mm 2 blade propeller. An m4 propshaft, not sure on length but you can order what length you want from marks model bits. Connect it to the motor with a huco coupling. Power threw either an mtroniks or action esc, i cant tell you what amp rating though. 8.4v nimh battery maybe, try component shop for that.