The OP is wise to limit his loads since the Uberti and expecially the Henry should stick to near-SAAMI pressures. IME stick powders like 4227 and 2400 don't work very well at standard .45LC SAAMI pressures, although they do bulk up well and eliminate the chance for a double charge. They burn very dirty, 2400 in particular, and if loaded to burn efficiently the pressures are too high. Neither Hodgdon or Alliant recommend them for the .45LC.
I have not used TrailBoss but it sounds just like what is needed. I have had good success with BlueDot at SAAMI pressures, it has considerably greater charge volumes than Unique does, although it would still be possible to double charge. AA5744 is another possibility, like 2400 it bulks up well, but it burns a bit cleaner; still not as clean as the flake powders do though.