Honestly, I would go with the Tim King. If you can afford the $$$ no reason to skimp out, a used tranny can just be a time bomb with your mods and the last thing you want is to get it on the dyno and shell a tranny because you wanted to save some money.

Get Panda going right and then focus on the Saab. 1 project toy, 1 DD... not 2 toys and bouncing with parts. Get 1 set and then do the other.