This is a great site. Lots of useful information on all aspects of Jeeps. They even have a Jeepster Commando Bulletin Board with all sorts of useful information.

These guys have some hard to find parts. Another cool thing is that they have many of the original Technical Service Manuals for Commandos, CJ-7, etc.

Aero Enterprise makes replacement fuel tanks for Commandos. The tanks are 23 gallons and from what I hear are very well made.