He is represented by several galleries but I would imagine that they would want a cut as well if you are cool with that. 
You may consider contacting him through social media if he is on it to see if he would be receptive to your commission request.
Hope this helps 

I hear the waiting list is many decades long

sufsean White cube is his main gallery from what I know and that they are taking the inquires of commissions.
I think his pa only deals with press but ill send you the adress and you can make a try.

jbelleit Not sure what you mean with original prints, but both originals, prints and hand finished prints is normally released thru the gallery who host his shows, and that varies a lot it seem. But normally white cube sell some hf:s of every print.

You can keep an eye on White cube, other criteria, reflex amsterdam, galleri maximillian, Ingleby gallery and blain southern.

White cube will have a show this summer and are as said above his "home gallery".