I think your plans are wonderful !!
Except for about 10 items ,most of which have already been mentioned.
There is a "Law" in boating
that can not be ignored..That is that for every day you spend on a boat with someone else,the boat gets smaller by 1 foot every day or so..human nature being what it is!
Your idea is a good one but it is far too late in THIS year to make a trip like this safely.
I have a very good buddy,,, he does yacht deliveries around the world [lives in Jackson hole,Wyoming]
3-4 years ago a rich [ I mean rich ] asked him [my friend] to captain
his Hinchley 59 around the world with a few of his buddies. This boat was in wonderful condition ,only 4 years old.
The rich guy told my friend to fix the boat up so it was safe for a trip of this nature. He did so ...it took him 6 months to ready the boat and the invoice the rich guy got was for $305,000.00 U.S. he didn't blink ...
They went ,they had a great time and everyone returned safely,,[every weekend the rich guy flew home to attend his college football games and then fly back to Fiji
the reason i tell you this is: 59 foot boat with 5 guys on it and it got crowded...to put your unknown boat in such condition that you would be safe and not kill anyone would take many thousands of dollars [20-30 +?????]
I always follow is that what ever you think about doing or going or buying
that you ALWAYS put it in writing..you may think I am just being anal but if you want to buy a dingy....put it down on paper .if you want to put larger fuel tanks
on board,,,first write it down[how big ,where to locate them on the boat and $$$$$$..
new radios /SS band??? put it down on paper..If you don't do this you will be very sorry and very broke..
I want you to go ,,,but you are a few years away from being prepared..
just one mans opinion
your mileage may vary