With what I bought, I used the Phantom jig from Stealth Arms, and all the rest of the fitting was done with files and sand paper for the most part. There are a few holes to drill. Of course a bench press is best, but if you are super careful and use the jig, it could be done with a hand drill.
A good, solid bench vise is needed for the slide to frame fitting. You can probably get it closer than I did with files, but I got it close, and then lapped it with lapping compound and a rubber mallet.
I think the only other tools a used were a counter sink for the hammer and sear pins (but it being an aluminum frame, I was just able to do this by hand), screwdrivers for the assorted screws (grip screws, grip screw bushings, and mag catch lock) and an assortment of punches needed for assembly.
If you buy a full kit from Stealth Arms, there will be a little less fitting of each piece I bet. I had to blend the back of the slide with the extractor and the ejector, but that’s probably because I was using WC components.
Outside of the countersink and the Stealth Arms jig, I really didn’t have to buy anything else. My dad was a gunsmith in his younger days, so I had access to all his tools and supplies. Admittedly, I’m only talking drill press, big rubber mallet, lapping compounds, and sandpaper. I already had bastard and needle files and everything else.
The bastard files were from Harbor Freight, and that I can recall, only used on blending of the back of the slide.
Needle files were used throughout for fine fitting. They can be had at most hardware stores.
Countersinks can be found on Amazon, or you can just use a drill bit depending on the angle on the tip of them.