Diesel Jetta

Hello folks, I'm a old newbie, old in age, but new to these boards. I am trying to find out information about Diesel Jetta engines. I have a VW Trike that is currently powered by a 1600 Single Port air cooled. I want to convert it over to diesel so I can make my trike run on Veggie oil.

Now you probably think I'm crazy, that's ok, I get that alot.

I also need to know if a diesel has the same connection at the transmission as the standard gas model. I hope it does because then I can use a standard Kennedy Engineering adapter to hook a Jetta Diesel to my trike.

Were there 4 cyl and 6 cyl diesels or just 4 cyl?

Thanks for all the patience with my many questions. Any suggestions would be appreciated as to what VW diesels to avoid, vertina models better than others, cheaper than others, turbo or none turbo...etc.

Thanks
Greasy