The top hull solution had come to mind early, but the external structure of the impulse deck has to remain exposed in a TMP design. So much that is possible with TOS just doesn't work with TMP.
Putting the shuttle bay down and behind the warp pylon, almost as a secondary hull is the idea that I've liked best. It maintains consistancy with the Enterprize, and as this ship will be a kit bash, allows me to simply use the hanger door from a the same model.
Still, my D5p is years away from completion. I'm never doing anything this ambitious again. I've made the gunboats, including a leader and scout. The boom, an all original design is done, except the paint. I still have to put the front detail on the warp engine nacells.
The sticking point I'm working on now is the maintanence bays. How can making such a simple shape be so difficult? Once I can make that shape, I can make a mold, pour some plastic, and use my brother vac-u-form to make the actual parts. I never should have started this!
The Federation destroyer will be a simple kit-bash. The classic Saladin idea just doesn't look right with the size of the Enterprise refit, so I'll have to use AMT's TOS Enterprise for the primary hull. Details will come off the AMT's Refit kit. The engines and main deflector will come off Bandai's 1:800 scale kit. A single engine doesn't look right, but the two small nacells look right with the TOS saucer.
If I could just find some nacells of an intermediat size, I'd think about a New Light Cruiser. Kahn's ship must have been some varient of a New Heavy.