A TMP Enterprise Class CH hull with a Knox saucer makes the Pittsburg Class heavy assault cruiser (CHA) from FASA's Star Trek game.
I made a model, for use in the LAN games here, last year, from the stock game ships, just to try out the concept.
There are quite a few existing "paper" concepts in books and on line, plus other posibilities for future designs, using the Knox or Darran shortened "D" shaped saucer.
Now a battle ship or CVM would be a logical progression on this design.... or maybe an SCS.
Isn't 3600 used by the Commanche Class FHA.... or is this where the donor saucer came from??