Visited Missoula recently. Here's the scoop:
There's lots of shops in town that rent boats/paddles. Edge of the World
http://www.edgeoworld.com/zoo/index.html is a great shop.
Edge demo'd me a project 52 and a Werner player paddle for nuthin' so long as I was going to the wave, talking good about their shop and letting others try the boat.
After taking advantage of this arrangement for 3 consecutive days, I tried to be a good guy and got them a 12-pack 4 their troubles, but dropped it on the their floor and caused quite a mess. (Doh!)

Luckily ony two beers were lost!
Brennans wave was running about 3000 if memory serves. It was a great feature, fast, deep pocket, spin and wheel city. Loops if you're a loopy type of person.
Try to hook up with Chucky and his gang in Missoula...dude and his crew took me down Alberton Canyon - Easy III- run with awsome (friggin's sick) surf.
Great boater community. Edge of the World is two blocks from the park, you really don't need a car if you don't want one. Hang out at the wave, and you'll definitly meet some people to paddle with.
Fun town! Enjoy.