One trimaran that might work for you is a Chris White-designed Hammerhead 34. New, they cost about $100,000-125,000 depending on how you have them fitted out. See here for more info. It has a double in the aft cabin and a single forward.
If you really need the space and comforts of a catamaran, I like the Gemini 105Mc a lot. It's a fairly narrow catamaran that will fit in a 40' slip, unlike a lot of its competitors. It is 34' LOA and has a 14' beam. The boat has a three cabin setup—a double berth aft in each hull, a master berth forward in the main hull on the starboard side, with the head forward on the port hull. The galley is in the starboard hull and nav station is in the port hull. The salon, u-shaped can convert to a double berth.
One thing I really like about the Gemini is how well protected and comfortable the helm station is. The helm, which is in the cockpit is under a hardtop bimini, and there is an optional enclosure that allows the cockpit to be very sheltered. Boat has a draft of 18" with the rudders and centerboards up. Board down draft is about 5' 6" or so IIRC. Engine is a Westerbreke diesel inboard using a Silette Sonic Sail Drive leg.
I've written about the December trip as well as the delivery on my blog and have a short video up on youtube from the Fourth of July trip to Cuttyhunk on the Gemini.
I helped delivery one of these from Annapolis to Marion, MA last spring, and also help move the boat from Portsmouth, VA to Belhaven, NC in December.
Other small cats that might qualify are the Maine Cat 30 or the TomCat 9.7, or the Seawind 1000XL.
The Maine Cat 30 only has a single daggerboard in the starboard hull. This can be a problem in heavy weather, where you really want only the windward board down to help minimize the risk of the boat tripping on the board. The MC30 is powered by two outboard engines. The master berth is aft in the starboard cabin with the head forward in that hull. The port hull has a nav station that converts to a second double and a very large single berth forward.
The Maine Cat is a bit unusual in that it has an open bridgedeck design. The salon and cockpit are all open to the elements, with only a hardtop bimini over the salon. There are separate entrances into each hull. Personally, I'm not a big fan of the design, as the helm is fairly exposed and the salon is essentially unusable in bad weather.
The Tomcat 9.7 is 32' LOA and 16' wide, so is in-between the MC30 and the Gemini in size. It's layout is very similar to that of the Gemini, with a double aft in each hull, and master berth forward and the head in the port side hull. However, the master berth is accessed through the head in the port hull, which is not an ideal setup IMHO.
The helm is very similar in setup to that of the Gemini, on the starboard side of the cockpit. Boat is powered by one or two outboards. Like the Gemini, the helm is fairly well sheltered under a hardtop bimini that is part of a partial enclosure.
The Seawind 1000XL is actually the largest of the boats, despite its name. It was a 10 meter boat that got "stretched" by extending the hulls aft. At 35' 5" LOA and 19.5' wide, it is slightly bigger than the others here. It has two different cabin layouts, both of which have four double berths. The main difference in the layouts is the position of the head and the fourth double berth, as you can see in the two drawings:
It is outboard powered, with twin outboards in wells, like the MC30 and the TC9.7. It is also the only boat with dual helm stations. The salon is open to the cockpit—and only closed off via a canvas enclosure IIRC. The helm stations are fairly exposed, more so than any of the other boats IMHO.
Of the four, I am most familiar with and like the layout and design of the Gemini the most. In terms of full disclosure, I own a Telstar 28, which was made by the same company as the Gemini up until they split the two lines last year. The Telstar 28 is a much bigger boat than your Corsair, and has 6' of standing headroom throughout most of the cabin, which is one reason I opted for it over the Corsair. If you have any questions, please let me know. I hope this helps. :D