Pacific Seacraft 25, Flicka, and Dana($$$ out of the 20k range) are all trailerable. Nor'Sea 27 are barely trailerable (10000lbs.) Your requirements really narrow your range. However, if those are your honest wants/needs, then the Flicka is going to be your best bet. Some people sail Flickas all over the world; Carib, South Pacific, Great lakes, Atlantic crossings, etc. Check Yachtworld, Pacific Seacraft Boats For Sale
Also check out the Flicka Friends newsletter, Flicka Home Page
There are no other 20' boats like them on the water. What other 20' boat has 6' standing room?.....none. Good luck with the search.