My next boat will likely be the Bayliner Classic 222 with the hard top option, trim tabs, etc., etc.
http://www.baylinerboats.com/cruisers.asp?modelid=44209&year=2005.
It's trailerable (5500lbs with trailer), 8cyl 220 hp merc I/O with the Alpha 1, has the hard top option, enclosed head (holding tank option), large open stern area for dive gear/guests, large spacious v-berth (or you can have the table up and seat 4 adults in the cabin), 21 degree deadrise, trim tabs, etc. The specs are listed on the website. It does not come with a swim platform and this boat is 22'3". I know of people who had a full platform added. Many boats with swim platforms (standard) have a door leading to the platform. I prefer a solid stern for rougher water considerations. This boat with the options I mention above MSRP's for just under $40G. This keeps the insurance costs relatively low as well.
The next step up is a (24'9") Classic 242. This boat offers different options and has the swim platform, etc. but it offers less deck space. I overnight quite often but most of my time is spent on deck. I never cook when on the boat so I don't care to have a galley. (When we weekend, we are going out to eat or eating sandwiches from a cooler).
I currently have the Capri 1952 (19' cuddy cabin). I often dive from this boat with three divers with doubles, stage bottles, etc., etc., etc. and someone to keep watch. Coolers, 02, sleeping bags, etc. are kept in the cabin.
Good luck with your search.
--Matt