I have a very similar .45 - the CVA Hunterbolt. Mine likes the following bullets in order of most - to least accurate:
#1. 200 grain SST/Shockwave
#2. 200 grain XTP with Harvestor light blue sabots
#3. 195 grain .357 Dead Centers
#4. 225 grain Powerbelt hollowpoint
All of the above bullets will shoot 2" or less groups at 100 yards with the proper powder charge. As for powder, I'd suggest 777 loose or Pyrodex loose if you prefer, as opposed to pellets. CVA doesn't recommend going above 100 grains of loose powder with the Firebolt, and I don't recommend it either- it's really not necessary. For example, with 100 grains of 777 FFFG, I'm getting close to 2,100fps with the 200 grain SST - you really don't need to go faster than that for all practical purposes.
Hope this helps!