I was going to do the same thing to my adventure until I did some research. My Hobie dealer told me it would be more expensive to upgrade mt Adventure than to just trade it in for an AI. Of course, that factors in some of the installation costs, but it's something to consider. Also, the AI doesn't have the capacity to carry two people. I wanted to sail with a partner, so that was a deal breaker for me. I'm currently trying to sell my Adventure and buy a TI.
2011 Hobie Mirage Adventure
ST Turbo Fins, Sail Kit, Sailing Rudder, SideKick Ama Kit, Daggerboard, iComfort Seat Pad, GoPro Hero3+
2007 Hobie Getaway
Carnai Trailer, Wings, SLO Wing Covers, SLO FWD Tramp, Cheata Mount, Suzuki DF2.5