I am leaning towards the Tekno clutch. I mocked up the clutch and bell and it fit pretty good. I just need to move the motor mount back about 10mm and raise the diff to get a little more bell clearence. I can easily raise the diff by moving the spacers from the top to under the diff mounts. I will have to drill new holes to move the motor mount back.

I turned down a Traxxas flywheel to match the bell diameter.

If I raise the diff the cutout in the diff mount will match up with the bell and allow a little more clearence. I will also countersink the motor screws for more clearence as well.