First post here on SailNet, but I've been lurking for a while.
I sailed dinghies and windsurfers as a kid, but have recently started cruising and racing (albeit poorly) larger boats as crew.
The boat I have sailed the most is my father-in-law's, a Pearson-Invicta. She has a combination shoal keel and swing keel. With the keel up her draft is just a hair under 5' and down it is around 8'. I am not sure if there are many modern boats with this kind of design, but may help split the difference a bit between safety and being able to gunkhole.
Another idea is to carry a sailing dinghy and use that to get up the really shallow areas. This can be loads of fun.
I sincerely hope you can make your dream happen of long term cruising, whether it is just continental or circumnav. Good luck! And don't forget to write so that all us beginners can learn from your mistakes!!