This one seemed to have the highest rating and the best finish:
http://www.etrailer.com/pc-HA~V75090.ht ... medium=ppc
(cheaper on Amazon but they don't list all the specs).
I'm going to have to use and extension adapter to clear the rear bumper also, so the tongue will be reduced as will total but my beloved boat (Sea Pearl 21) only has a tongue of about 100-150 and my cargo bag will only have light stuff so I think I'll still be well within safety margins. Total boat weight (with trailer) is around 1000-1250 loaded).