Looks like the way to go if you can afford it , It may pay out , what with the price of gas .
The main problem I can see in your idea is that I don't belive VW ever used a north/south transmission.

The Rabbit / Jetta / Golf / Passat are all transverse FWD
The Vanagon / Bugs / Beetles are all rear engine transaxle
The Fox has an inline engine but is FWD with a transaxle .
The only option I can see is to buck up for the kit .
If you find a better / cheaper solution I would love to know .
