Do you mean you are trying to find a motor and mount to rent? Or need someone to join who has one? Or want to buy?
Other 'buzzards can chime in, but I don't know of anyone, anywhere who rents - liability would be a killer. If you want to invite someone with a motor, that's another issue. As for buying, look locally @ Craigslist, ksl.com on the western slope, local classified ads in "free weeklies" or newspapers. You can cobble together a mount/transom pretty easily, the appropriate motor in 3-6 hp. range is what you need to find....