I've had the best luck with small independent MC shops. They usually don't ask a lot of questions and just do the job. The problem is finding 1, it looks like the last place I went in Waukesha is now out of business.
Call them and let them know up front that you are bringing your own tire & wheel, and ask how much mount/balance will cost. Last summer I went to a dealer in Madison and had a front tire put on a wheel (I brought in both) and assumed I would get charged around $25-$30 like many times elsewhere. The bill was $60! They charged 1/2 hour labor.
'05 1800F2, Cooper Zeon ZPT 215/45/18 40-42psi, Thunder Tornado, C headers w/Roadhouse Shorty, C risers, C fender grab rails, C passenger peg brackets, desmogged, BrakeAway Cruise, Mean City Cycles memory foam.