Hi Greg, DU alum here!
Take your time looking for a boat. When I decided I wanted a 14' raft to be able to take my family boating, I started looking in January. It took me close to 4 months to find a boat in good enough shape, for a decent price, before I put my money down. So figure out what you want, then put your money aside, someplace safe and just keep looking. With time on your side, after all, it is September, you will find what you want if you keep looking.
So what's the alpine club up to? When I was there, the club was my introduction to rafting and kayaking.