Nice ride where did you get the fork from? I am going to do something like yours except with a frame mounted engine. How comfortable is the banana seat been thiking of that too?
The fork came on the bike when I bought it off of craigslist. The only thing I've changed is the front flame sprocket and I rebuilt the bottom bracket. I know you can get one for $85 here:
I really like the banana seat and sissy bar that also came with the bike when I bought it. It makes a nice ride, although there's no suspension. You might be able to get one of those spring seatstays to help soften the bumps. Hope that helps!