I was thinking of going with the powerglide for ease of installation, but he seems to think that adapting the 4-speed shouldn't be too bad either. So it's the 4-speed as the 1st choice, with the automatic as the back-up plan.
Brady,
keep in mind the vair engine rotates counter clockwise and you would have to install a "reverse rotation kit" thats if you could find one. This means the vair engine would have to be rebuilt. You could flip the ring & pinon in the tranny ( assuming its a swing axile ) but then its rotating against the bevel and pushing a heavy vehicle that will speed up the wear. I'd rethink the powerglide, they can be beefed up very easy but even in stock form should be able to handle the weight issue.
This is off the topic but take a look here for some interesting engine swaps. Tons of powerglide to V8s plus lots of "flipped vair 4 speeds" midengined V8s
http://v8vairs.com/You should swing by when I get to the swap stage...You're one town over from Oaklyn...
just give me a yell when you start, I'd love to see this one..