Hey. It depends on how big it is, Going geared will get you a faster climb, at the expense of top speed. I am working on a sp 400 7.2v design for 3 lipoly that will do vertical on 3s1p et-tech 1200: geared 4:1 with 10x7 prop looks a likely starting point.
However, it won't ever fly at more than 40mph.
just thought that plane looked like it ought to be screamingly fast. And noisy!
perhaps a couple of Cox 020s would do the trick
They run both ways ...