single speed coaster brake problems

Okay, So im working on my first hybrid bicycle, and I thought I had chosen some ideal candidates for the project. I bought a Dynoglyde single speed with a coaster brake. It looks great with a sloaping shwin style frame all in yellow. To power it I have a heavy duty new winch motor rated at around 750 watts with a planetary gearing system built in, a 153:1 ratio, but now modified by taking out the last stage it runs around 13:1 (little bit louder, but very compact). The frame had a great mounting spot where the chain from the pedals to the rear wheel ran on the right side, and I planed to place the chain from the motor (mounted beneath the seat) on the left side. unfortunately the left side of the wheel also contains the coaster brake bracket (mounts from the hub to the frame). This makes it very dificult to mount any gear on the left side for the drive chain from the motor. I monted a freewheel directly to the motor gearings to make the system as simple as possible at the wheel, but am having trouble finding a way to attatch a drive gear to the rear wheel that is both sturdy and centered well while not interfereing with the hub style brake. I realize that this brake style will probably be inadiquate for high speed, but I plan on going no faster than 20-25mph, and am replacing the front fork with one that has brake mounts as a back up.

Does anybody have any good sugestions for mounting a gear to the rear wheel for a single speed with a rear hub break? I realize that this is probably a question that will just need some good ol R & D but if anybody has come across this or similar problems it would be great to know what you did to solve this problem.