Installed a S&A beavertails on my older Springer. I like the fitted BTs better than the "drop-ins".
Mine is a pre-ILS gun so a mainspring housing change was simple. But I'm pretty sure your spring and plunger would work fine in a standard housing. I prefer the arched housings, but that is personal preference.
With the cost of parts and tools, refinishing equipment and supplies to do this yourself and do it right, won't save you a whole lot of money, and you will void the warranty. Also if you do mess something up you have no one to blame but yourself, and you may be dropping more cash on second sets of parts. Not trying to discourage you from doing this, just giving you more data to weigh in your decision. I obviously opted to risk it, and bought the BT, the fitting jig, the stones, the new hammer, the hammer and sear fitting jig, the parkerizing kit, and I already had an air compressor, air brush and Norrels Moly Resin for the final baked finish I wanted over the Parkerizing.