Looking for gy6 engine with external reverse

[Skizee]

Hi I just found the site and was wondering if anyone can help me to find a gy6supplier in North America that sells a gy6 with the external planetary gear reversing drive 1:1 ratio or the same ratio in a internal reverse gy6. I am a cnc machinist cad/cam programmer and we made a prototype drive unit that pushes you on a set of skis. We wish to try a gy6 engine but found the rotation to be the wrong direction, thus the reversing gear question. the you tube link is the unit we are going to try the engine in.

http://www.youtube.com/watch?v=jtaiI5NyZ5A

Cheers Adrian