Yeah - the Skyhawk is for my winter project, it's an addiction man
Honestly, much as "custom" builds are awesome - if you really want one of these "80s" I'd seriously consider getting another bike (one the motor fits on). Used bikes are cheap as heck, I've seen 'em fer $15 at yard sales - even a Walmart special for $100 or so just to see what yer getting into.
That way you know the build wont be a problem and you can ride yer bike all the sooner. You can always switch the gear over should you want to/figure out the mount issue.
I think yer bike is perfect for a rack mount... but it's yer baby and I can't wait to see what ya do w/it!