You have a lot of things competing here. Building a custom hull would not be to err on the side of affordable. It means you'll assemble the rest of the
boat from
parts and pay a premium even if you do all the assembly
work you won't save
money. If on a
budget I would never build your own
boat let alone hire it done if saving
money is a consideration let alone a requirement.
I wouldn't go for a motorsailor. It's the worst of all worlds. They sail almost always poorly but still require all the
rigging. Being light weight does not reduce operating costs at least just on it's own. Using
wood anything won't reduce
maintenance costs either. Maintenance is not low on any boat and dependent on climate greatly.
I think you would do better with a used
power cat. It's the only thing I know of with 6 - 4
headroom everyplace. They haul more stuff and have more square footage. With two smaller engines you might be more economical. Sailing
gear buys a whole lot of
fuel.
Bells and whistles can come in many forms. Hot
water?
Refrigeration?
Air Conditioning? Hydraulic crane for the
dinghy?
SSB or HAM
radio? TV? TV with
satellite receiver?
You have not indicated the type of travel you plan on either. If you desire to cover long distances with ocean passages you might have blown the
budget. Your list of requirements really needs more
work and next to it would be a more refined list of expectations with a budget.The budget needs to consider
purchase costs, operation costs, and other expenses to compute to a number that leads you to a total boat budget. In the bigger picture the cost of the boat is the only easy computation but only after all the rest are added up.