I'm trying to find someone myself. I would like a trigger job, staking on a new front sight, modifying and fitting a 1911 rear sight I like to the Hi Power dovetail (I've had that done before) and ideally adjusting the height of the front sight to zero the gun with its new sights, replacing the safety with an extended ambi one, replacing the hammer and sear with C&S ones, polishing the feed ramp (it feeds HSTs just fine, though, so no recontouring for me), and install a replacement lanyard ring (I can't find the press-fitted type this one had, so it would need to be tapped for a threaded one). I also may do refinishing work if I am going through all of this trouble, and I kinda want to replicate the factory finish, which is a matte/eggshell black anodizing on the frame, oven-cured satin black enamel paint over Parkerizing for the slide and sights (satin black Cerakote over Parkerizing works for me), and a glossy blued finish for all of the other parts. I kinda like the way it looks, like a subtle two-tone with highlights. Maybe clean op some nicks and things as part of the process.
I used MK3 last time, but I was disappointed in the trigger job and they decided to hack off a third of my rear sight which upset me (while not reducing its height which is what I actually wanted). They lightened the weight of the break to my liking, but the weight of the takeup was so close to the break that I couldn't find the wall easily which made it feel almost like a mushy, creepy trigger, and I also didn't like what was done with the takeup length, which was nice as-is (very short for a factory Hi Power trigger) but not as nice after the fact. They also only do Cerakote (and cold blue for touching stuff up) for refinishing. Prices were okay for the work, certainly quite good compared to some of the better Hi Power 'smiths, turnaround time was shockingly fast, and they were somewhat convenient to get to, being less than four hours away, which is a big part of why I went with them.
Seems like if I want anything else, though, I'm looking at limited options for the type of work and finishes that can be done, or the 'smith is no longer taking new work, or we're talking about exorbitant costs and/or (usually both) extremely long waits, both to be able to send in the gun and to get it back once it's been sent in. Don Williams would be the next most convenient distance-wise, but if he's not taking work then that is not an option, obviously.