Re: XDM Grip Stippling
Check out Canyon Creek Customs, Springer Precision or Powder River Precision. Lots of stuff for XDm's there.
I just ordered a built 4P from Canyon Creek after seeing one at a match. I was happy to pay the price for it. Very nice pistol and still production legal.
Lot's of forums specifically for the XDm out there that may be of more assistance to you.
Good luck and post pics when you are done!