I have experience with these 3. First pistol optic was an ACRO mounted to an aftermarket slide by KE Arms that I bought assembled from russell phagan (good guy). That has worked great, but as you note, these slides are hard to find and the internal components even harder to find.
For that reason I just ended up direct milling a ton of my guns using exclusively Jagerwerks or Maple Leaf.
Jagerwerks did my other ACRO cut for a Glock 19 that I will eventually mount the new P-2 ACRO to when mine finally ships. Very happy with their work. Biggest downside is that I just wanted front serrations and not any other slide work. This saves at least $100 per pistol, but they will mill right through the lettering on the slide. It doesn't really bother me but in hindsight I would have chosen differently.
Everything else I sent through maple leaf, using their carry package. For an ACRO you'll want their
duty cut package which is $200 for a bunch of slide milling including optic cut of your choice and re-nitriding.
In hindsight, this is what I would have done for my ACRO. I would recommend you go this route vs Jagerwerks if you decide to direct mill as you get more work for less money. Their cuts are also extremely tight (I had to seat my RMRs with a brass mallet) which is confidence inspiring. The price is also hard to beat. See below for a photo of some of my guns. The 3 pistols with the OEM slides (17, 19, 26) are all Maple Leaf's work with their stonewash nitride re-finish + their carry essentials slide work. Couldn't be happier.