I have for sale a DB6NT 2m transverter, complete with all cables ready to plug in to a K3 with KXV3 and go. This is the Rolls-Royce of the transverter world, 0.9dB NF receiver suitable for EME work without a preamp, >20dBm IP3. A very clean 25W output from a conservatively rated and generously heat-sinked PA, suitable to drive a linear amplifier to the legal limit. New models list for EUR 1,380 today. Selling for GBP 700 + shipping within Europe only. Would accept Elecraft KX144 (internal K3 transverter module) in part exchange, if you have already ordered one but think that this would better meet your needs.
For more info and picture:
http://www.g4ilo.com/2009/09/db6nt-tr144h-transverter-for-sale.html . (Note: it isn't obvious from the photo but it is about the same size and weight as a fully-loaded K3.)