Choose wisely, theres nothing worse than a shitty mount staring back at you day in and day out.
The best way to judge a taxidermist is to look at his average work heading out the door. Dont look at a few pieces that are in the showroom. Check to see if the eyes are set right on the form, I've seen lots of mounts with the eyes all messed up (one lots lower than the other). Also, check to see how the antlers look on the form, not too forward or too far back. Look at the pose of the critter, how much they build up the forms around the eyes/nose with clay, how much detail in the neck muscles. Shy away from taxidermists that dont add detail just slap it on a form and call it good.
I also use mountain lions (lifesize) as a litmus test...they are tough to get right. I've seen more crappy lion mounts than anything. If a taxidermist gets lions right, they're normally pretty good.
All taxidermy is not created equal, and normally you get what you pay for. I'm kind of critical though, as I used to work part time at a taxidermy shop. I only trust one taxidermist with my stuff, but he lives in Montana...