I talked to BK again. I was wondering if their R-9773 brackets would mount the Recaro seat directly to the floor. It won't. They don't have a solution to mount it without sliders (which seems odd to me). If I have to, I'll fabricate an adapter myself for track days to get that extra inch of clearance.
Anyway, while talking to them again, I found out that the R-9062 (which is for use with the Sparco or Recaro sliders) WILL work with the anti-sub bar. It's just the R-9062s and the sliders aren't drilled out for it. The guy I talked to was one of the engineers at BK and he told me that lots of people do it and it works well. So it's not a clearance issue, it's just that the parts need to be drilled. BTW, the BK guy was VERY helpful.
So what he said to do is put all of the hardware together with the seat out of the car. Determine where the sub mount bar should be located. Mark the holes. Take it all apart and drill the holes with a cobalt bit. Since the BK parts are made of stainless steel, you have to use a cobalt bit or you will go through a ton of bits trying to drill it out. Finally, put it all back together. The holes need to be drilled in the bottom of the seat side brackets, and in the top piece of the slider.
I ordered all of the stuff I'm going to need from
Stable Energies. The guy I talked to there was also SUPER helpful. After I gave him the list of everything I was ordering, he offered to have one of his installers double-check to make sure that should all work. Of course I took him up on it. I should have all of it on Tuesday, so I'll update the thread with the comparison between the seats then.