diesels will serve you well, but you have to be ready for things like glow plug relays, glow plugs, coked up rings (if not well maintained) and of course, the issue of rust on all these cars.
Seattle is a good place to look for cars (as is the PNW).
City Motors on Aurora and 83rd is a reliable place.
Remember these are 30 year old cars and will need help. So have some cash reserves for problems.
Craigslist is a start. I'll include what I found last summer to get you started.
VWvortex Forums: yellow 79 wabbit
Look at a lot, a lot of cars to know what is worthwhile.
Good luck