I would look for and buy a boat now. Something for maybe $15,000, in the 32 - 35' range. I also would buy a full keel
Do whatever work it needs to let you start sailing. Then start sailing and working on the boat, and finding out things you want to add to it for the big trip.
Sail it every chance you get. Especially in very bad weather
. Out there you can't head
back to port when mother nature messes with you.
Take vacations on the boat in the Gulf. Learn, enjoy, and work towards the goal. Just be sure to do it!
When I bought my first real (with a jib) boat the owner who became a good friend, gave me a drawing of a sailboat sailing off in the sunset, with the saying "With dedication, dreams become reality"
I stuck it up on the wall and looked at it often, while making sailing plans.
There a lot of older seaworthy
boats out there in need of TLC for a decent price
. Buy one and it will be the first step.