There is a community out there and many people who will be willing to help you get out on the water. Go for it.
This page has some info on modifications etc. We rafted with a guy in the past and he did some stuff in an IK but that was hard due to stability issues. I was so nervous the first time we went out for a day trip and everyone got turfed out in the second rapid - of course, with all that upper body strength Per was the first to climb back into the raft, ha! He was only here for a couple of years so we only did a few trips. Per preferred sailing and will be representing his country for the fourth time in the Paralympics at Rio, amazing guy.
Perhaps the coolest thing was the Lower Salmon trip we did when on the first night Per wistfully said that he intended to sleep under the stars as it was the first time he had been away from roads since his accident. That memory still brings tears to my eyes.