Rear brake upgrade (again, lol), Or,how to get a vented rotor Options

[HalfMoon]

So I know this has been talked to death thousands of times and when I do a google search there's reems of information, but rather than spend the entire evening reading through many posts that really aren't relevant, I thought I would pose the question and see what turns up.
Recently I had a four wheel alignment and corner balance done by a really great and well known shop out my way (who are very familiar with track cars for my local track-Summit Point) and when I asked the primary mechanic today what things he might suggest for my sbc Sheridan standard wide-body conversion, he said upgrading my rear brakes would be pretty important for that track.
Soooo, yes there are lots of ways to go to be sure but I was wondering about retaining the standard rear 914 brake (and e-brake) but using the vented 911 SC rotor? Do I recall Eric made/makes a spacer for this or is/was that for converting 914 fronts to rears?
A lil confused this particular application.
I like the idea of retaining the stock 914 rear calipers if I can but I really want to go to vented rotor (as opposed to drilled).
Thoughts?