I have read through many of the posts and see the transmission side of things can be the hardest part of the project - and no wonder - there's hardly any space in a bike once one fits in the Diesel donk
Here is a few ideas I'll put to you in regard to CVT Technology
Here's a link I think some will find interesting http://www.fallbrooktech.com/NuVinci.asp Now how great would it be to have someone come up with a way of putting all, or some of the transmission in the rear wheel hub
Here's another link I think many would like to have a look see http://peswiki.com/index.php/Directory:Transmissions
The good thing to see with all the guy's here on the forum and on Stuarts Dieselbike site - you think individually and make some of the best individual machines that are unique. So I guess what I'm trying to say - keep thinking outside the square, and if a idea comes to you, jump on the net and have a look around, you'll be surprised what you'll find.
Now the two links I've posted are only 2 of many I have, but these will give you the best kick along if your looking for a tranny that is different from the rest.
I'll keep an eye out for any other technology that I think might be useful and post it up in due time.
Cheers - and happy riding
Andrew