Francois
Road King trailer company makes what they call the "Trail-n-Sail" style trailer, which is designed specifically for sailboats. I own a double-axle version for my E25. They do, though, make a triple axle version that would probably be able to handle your boat, if you used the largest tires available.
As Loren suggested, you must be cautious of used trailers that have been in salt water. In my experience, good used trailers are hard to come by. I tried this route. I also spoke with a local trailer shop about modifying a non-sailboat trailer to accomodate a sailboat. The estimate I received was not much less than a new trailer. I therefore opted for a new one. As of this spring the trailer will have paid for itself in terms of the slip-fees I've saved, so I'm glad I took this path.
If you opt for Road King, make sure you ask for quotes from two or three different dealers. I saved a lot of money by shopping around.
Roscoe