There is
literally dozens of holster makers, production and custom, that make holsters in leather, for prices from $50 or so, all the way up to a couple hundred or more, either off-the-shelf or with waits up to three years. Unless you luck-out and somebody happens to be looking who just happens to have the same M&P you have, or a holster maker that has a form for that pistol happens to be about, you're going to have to do the research yourself.
There is an M&P-specific forum (/me looks thru his accumulated electronic detritus...) here ya go:
mp-pistol.com You might have better luck there, since M&Ps is
all they talk about.
Here's a gun leather makers list:
Gun Leather, Handgun Holster and Gun Belt Makers, if you want to approach it that way.
If you don't already have one: I recommend a
good gun belt. You can have the best holster in the world and it won't work worth spit if your gun belt doesn't support it well. (IME: Most of the gun belts you see at gun and sporting goods stores aren't all that good.)
Good luck!
Jim