go to bullet central. The main substantive variation of BR triggers seems to be the 1 stage vs 2 stage r700-clone models. The Tac-sport-pro-X, etc are for PRS and have completely different internals vs the "true" BR-model triggers.
Many variations in both models IMHO are not substantive, eg right hand vs left hand or various sear heights or various trigger shoes, with or without safety. The sears and trigger shoes are typically modular internal components, so if you buy a trigger with one setup, you can later swap out components to replicate other configurations.