Actually it depends where you are to if they do or not..Azura, they might near you, but that's actually not a normal thing. No salon I have EVER asked will do them. I've asked in 3 cities and not a single one will. This was when I didn't know how to. The only "salons" that said they would were people that upon asking "how will you cut them" their reply was "Just like any other person's hair, of course, it's not any different" when if fact yes, it's VERY differnent. Cutting a wig the way you cut real hair will look extremely horrible, so the ones that will do it, usually do it because they have no idea how to actually ct a wig correctly..
Honestly, find a commissioner if you are that worried..