I wonder if getting taller shocks that would raise the back end 1" would help in the handling department? I went to the Metzler 880 on the front which is a taller tire than the stock ME33 on the Speedmaster. I thought maybe raising the back end might help in the twisties.
As far as a chopper goes, I would think going to a local frame builder would be the best route. At the least just picking their brains for ideas would be a benefit even if you didn't end up getting a frame built from them.
One of the benefits that is coming out of the AMA Grand National flat track bike that Bill Gately of Bonneville Performance built to race, is that sometime in the near future you'll be able to get a flat track frame, or a complete street tracker build, for our engines. No word yet on when this is going to be on the market.
I leaarned this from his post on the Delphi Cafe Ace forum where he posts from time to time.:
"The street tracker plan is in motion just waiting on the build for the mile bike before getting into the finances necessary to prototype a street version. This bike will also be a frame up build with a 989 stroker but your choice on a 270 or 360 crank."
Mecatwin in France does a great looking street tracker, but they won't sell the parts and ship them here.
Mule Motorcycles did a street tracker for Triumph that's been touring the industry bike shows.
Of course all of the above costs a bunch of money, but I can dream.