Why not get a low hour home built? You can then do all the maintenance yourself saving you a lot of cash over 20 years but you do not have to build it. There is a lot to choose from and you can keep it bang up to date with a lot less cash. Have a look at the Sport Cruiser, the P300, MCR01, Tecnam and probably several more. If you are thinking of serious touring do keep an eye on the wing loading. Some machines are much more prone to turbulence than others. Big variations in speed and load carrying as well.
Rod1