I don't know anything about putting one in a vanagon but I do know that these engines rule. They are virtually trouble free. That is the same engine that comes in the VW Quantum syncros. They will go 300,000 miles with just typical maintenance. While you are looking you should keep your eyes open for an MC code turbo motor. If you could fit the regular 5 you could probably fit the turbo. The inline 5 is rated about 120hp and with very little messaging you can get over 200hp from the turbo motor. Both are very reliable.
good luck and keep us posted,
Craig
the Gorge VW Club
gorgevwclub.com
ps - You can see a shot of the Turbo motor in my Quantum Syncro on the club web page.