I was going to suggest the same thing. Start with something that is really solid--even if it's been off the road for years. Welding takes a LOT of time, and for a really rare car it's totally worth it, but you shouldn't have too much trouble finding another, more solid Super Beetle to start with....
My Uncle actually has 2 for sale cheep. They're solid but they're dissassembled and have been off the road a while. Most people look at a dissassembled solid car and think, "Whoa, there's a lot of work". But if almost no rust repair is needed, the work is WAY easier.
Check out the rest of this site to see the 6 months of welding I did on my 356 Porsche. It's a ton of work...
I have restored a '75 SB convert that needed floors and some other patches, but with a convertible you can always sell it and make some money to compensate for your time. A restored super beetle only goes for 4-5k, though it takes as much work to weld back together as a car that goes for more moola when it's done.
Good luck! Here's my Uncle's phone number. He has 2 Blue 70's beetles--not sure if they're supers...
763-432-2705. They're in Minnesota though...His name is Jerry.
