I have been searching successfully this summer for composite 16' Tandems. I now have two 1970's Klepper Kamerad TS kayaks that are available. They will be for sale in July. Your choice on sail color.
Lately I have been setting them up with two 32' BSD sails, a Long Haul mid mount board, one BOSS and two Lee Boards. Cost will be approx. $6500 picked up here in Woodbury or at one of the Sail's Angels gatherings.
A Long Haul Mid mount board is a classy way to add strength and stability to the hull for the extra forces of the two sails and 2nd lee board