As long as you can find data any of the powders you listed would work well in the .32 S&W Long. In the modest amount of .32 I've reloaded I have used Red Dot and Unique because that was what I had data for. Charge weights are small and a .1 grain increase gives a bigger change in velocity in the small volume .32 than one sees in the larger capacity cases. Most of the current data I see for the .32 S&W Long only list velocities in the 700 fps range. The data I had came from an old Speer #9 manual and the loads ran 900 + fps with 98 gr lead bullets. Your solid frame Colt is strong and capable of relatively high pressure loading and with a 6" barrel 1,000 fps + is easily done if you want a more potent load.