Ned,
The fluid Tremec had made to their specs is this:
https://www.summitracing.com/parts/awr-tukt-16993
Not sure who's making it for them. Pennsoil, Valvoline, AMSoil, and Royal Purple all seem to make variants of syncromesh fluid.
While I haven't tried it yet, it's probably hard to go wrong with the fluid that the manufacturer says will have the best results.
As far as the Redline shockproof, I've tried the lightweight and superlight shockproof in the T56/TR6060. The lightweight shockproof is thicker and will better dampen gear rattle, but IMO it's too thick and makes the already notchy T56/TR6060 shifting (especially into 2nd gear when cold) even notchier. The superlight shockproof is better suited IMO.