Usually a monohull
sailboat will have similar but not exactly equal space when compared to an "express-" style powerboat. Saloon
, and staterooms below deck
on both, plus cockpit
-- but usually also with a "bridge deck" for additional space on the powerboat.
Powerboats also tend to be "fatter" than monohull
sailboats for the same length, and the amount of that beam carried over the length can add quite a bit of volume. Then too, powerboats with raised saloons, and of course flying bridges, expand on that space quite bit.
Exceptions to all that, of course.
Then there are catamarans, either power or sail. Both can add volume, some able to compete with monohull powerboats of longer length.
I'm not very familiar with sail brands/models... but if the old Chris Crafts powerboats float your boat, you could look at similar from Hatteras, Carver, boats with the word "tri-cabin" in their name (might be a Viking like that), maybe some old Marine
Trader "trawlers (or Grand Banks
, at the higher end), etc.
Another search key might be to looks at "aft-cabin" -- or "trunk cabin" in trawler-style boats -- or "motor yacht," which some makers use to imply an aft cabin
(contrast with sportfish and "convertible" boats, which don't usually have three cabins until you get into the 45' range). An older aft cabin motor
yacht would usually have the owner's stateroom at the stern (abaft the engines) and one. two, or more cabins forward.