I think the central idea of this thread was that the customer has bum knees and the normal way of starting a bike with the shift kit would be difficult for him. A pull start would answer that problem in what is probably the simplest and most cost effective way and would be kind to the customer's knees. This is all providing the pedal does not run into the bit of additional width due to the pull start assembly. A pull start can be added on to any China girl motor for somewhere around $25.00 if I remember right. It would be nice if someone did an aftermarket pull start of superior quality or even just the guts of the pull start.
Which does not take away from thoughts about how to do an electric start. Norm wanted to know if something was available now. Apparently not. Hopefully there will be some experimentation and some viable options from forum members willing to pursue this. I'm not one of them. A pull start is too simple a solution and involves no batteries, starter motor, etc.
Another option worth considering (but maybe not for Norm's customer) is a kick start for the SBP arrangement. I see that Harry76 has made up one which engages a small gear on the end of his jackshaft. This can be seen on the Villiars Beach Cruiser build thread. I haven't given this much thought and maybe there is a reason why it could not work with the SBP kit, but if it works with a jackshaft on Harry76's then I don't see why it couldn't with the shift kit with the addition of a slightly longer shaft so that the little gear could fit on the end. Kick start is cool. I know, this thread is supposed to be about an electric starter. That's it from me on this subject. Carry on and good luck. Gentlemen, start your engines!
SB