
Nuatitud, "Us" know make's sense. I do not or have not sailed the TI (I have the AI) if it is anything like the AI to sail, learning to sail is not the issue for you they are that easy.
Your main concerns I think will be getting it on and off the water, storage and transport.
The suggestion by stringy and two carts is not a silly one, the soft tire's are harder to pull on solid surfaces but are slightly better on sand where as the hard wheels are a pig in the sand but great on solid ground. Personally I would go for a trailer and leave it on it, but for you and no ramps I would possibly set the trailer up with the TI pulled apart and put it together on the water front, that will make it a lot easier to handle (depending how close to the water you can get).
While it can and does be done, I think the TI is to heavy to lift for roof topping on cars, I suffer from back issues and cringe at the thought of people lifting these beasts (we aren't getting any younger

). I am not sure if you have the space (guessing you do because you had a boat) but if you can store a boat and trailer you should be able to store a TI on a trailer and I think you will find it a far better way to handle one.
There is a trailer for two AI's here in Australia that I think is great and may give you some idea's, it is in the start of this video I shot age's ago at a meeting we had down here.
http://www.youtube.com/watch?v=wu6gNjMdUbI not sure if the link will work in your country and sorry cannot find any photo's so best I can do.
Another extra I would get to make it more enjoyable for your wife is tramps and I would also look seriously at dry-suits for the future, expensive but well worth the money for all year round use.
Good luck in your choice, I think a TI may suit your needs, it's also a ase of will it suit yours but I think it will
