I went into a local Recaro shop, started poking around under seats, and realized that I was being a bit thick. I don't need a whole new slider and bracket - I can just reuse the existing ones. Duh.
The Recaro and Corbeaux seats all have plates on either side (running fore and aft) and their slider/brackets just bolt into these plates. The stock troopy seats have the same thing, but since the troopy slider/bracket is slightly narrower (12" versus ~13"), to be safe, I will bolt some flat plate (running side to side) in there. Nothing more than cutting some flat plate, drilling, and tapping.
This means that any seat with a flat bottom can be used, so I will hit the local junkyard first and see what I can find.
Cheers,
Chris.