Seems like the cheapest least labor intensive thing to do is try both. You are talking about a car with modified suspension with stiffer bushings and 1.6 lowering springs.
The power you make is going to affect things too. Finally, the rear tire width you use is going to affect your grip if you have a stiff setup.
My car has the smaller lowering springs and mostly original bushings(softer setup I expect). Especially the big stuff in the rear is original. The Bilsteins aren't too bad for my setup. I get a bit of wheel hop if I try to drag race from a stop to WOT.
Racing from a stop light and turning left 90 degrees at WOT my fatter than stock tires do slip a bit but it feels good. Your stiffer bushings and I expect stiffer lowering springs might exacerbate the situation at my Cobra intake level of power.
With your different springs and stiffer bushings, I'd expect a rougher ride with Bilstiens and might want to try the Tokico Blues.
One is going to work better than the other for your car. After that you can chase what the more custom guys here are doing.
I spelled Bilsteins a couple ways, hopefully one is right.
1992 Tbird LX 5.0, 3.73 gears, 1995 Cobra intake, deleted air silencer, 2.5" mandrel bent dual exhaust, SCP shorty headers. Updated four-hole fuel injectors. SK shift kit in AOD. Vogtland 0.9" springs, Tokico and Bilstein shocks.