The maximum capacity of boat in people and gear is not the operating capacity. I don't care if it says the 22 footer can carry 30 people, the fact of the matter is in practical terms it cannot.
CON8IV, I did not try to sell him a Whaler because while I like them there are plenty of other boats out there--as long as they are center consoles---lol--which the inflatables often are in this size range. A 32 foot Boston Whaler Outrage is going to run between 180,000 dollars and 200,000. Since I have never considered buying anything like that I have no idea if they will bargain or not---!!!!
(not our boat but it is a small BW Outrage)
Not huge truck pulling our not huge Whaler:
How much, well, 150,000 dollars ought to do it, remember, in the USA of Amurika, those rubber boats will get no respect and no resale. The Zodiac Pro Open with a 150 horse engine is priced at 41,000 dollars and is 21 feet long and has a max capacity of 11 passengers if they sit on each other. The larger military duty units with twin engines really could run up to 150,000 dollars. In fact, believe it or not, that will barely get you into a larger Whaler, boats are VERY expensive, about the only thing that costs more are airplanes. Of course, some clever shopping on an older hull, a rebuild and refit could get you going for much, much less.
OK, your not going to be able to carry 20 to 30 divers with two tanks each and tow it behind a non-huge truck, sorry to burst your bubble.
A 200 horse engine, Yamaha, Honda or Mercury is going to run you 15,000 dollars each, rigging is extra.
Let me give you something to think about, a typical small boat like ours carries 60 to 120 gallons of fuel. Our engine burns about 6 gallons per hour or more. Twin 200s would burn about 9 GPM each. I have a lot of stock in an oil company--lol--do you?
You might look into something roomy like this:
Just kidding.
Some of those boats in the links above are panga-ish. You either like pangas or you don't, I don't. Check these out, the 28 footer for example,
www.pangamarine.com .
Are you planning to carry divers for hire, you will need a USCG Captains certificate, the boat will have to meet regular inspections etc and there will be lot's of insurance.
Also, none of the boats in those links in your post can be towed by a small truck--as you asked --huge truck will be required and over width permits also.
Buying a giant rubber boat would be like doing this to your money:
N