Todd, you've been dealing with this problem for what seems like forever. When I started having knock back issues this thread was a wealth of knowledge on the situation. I read this whole thing over carefully, and went back and forth on how I was going to try to address it. Having seen all of the work that you did to try and find an adequate solution, I decided to go with a floater. I wasn't sure whether or not it would be overkill. Yes, tapered bearings and a 1" master cylinder have worked, Bad Penny being an example, but I didn't want to run the risk of having it not work, leaving me having to put up with the problem, or throw more money at it.
From the four autocross runs I did before I had to retire my car, I can tell you I didn't have any problems with the floater under the car. Hopefully nothing pops up after more track miles! I know you're tired of spending money on the car, but IMO the presence of mind in knowing that you wouldn't have to screw around later would be worth the 1500-2000 for the floater.
... You probably didn't need my little testimonial though
Feel free to give me a call if you are seriously contemplating the change, or give the guys over at Wilwood and Speedway a call. They worked together every step of the way, and came up with a solution that was very reasonably priced considering I replaced everything except the third member.
Matt