Do you live at a dark sky site and plan on doing a permanent mounting? Or do you plan to drive out to one to set up? That will kind of limit both the mount, and the aperture you'll actually be able to use.
For deep sky, you want a very solid mount (longer exposure with minimal tracking error), as big of an aperture that you can set up (the giant light bucket), and a good camera + various filters/accessories(I run a filter wheel with 9 filters for various things, various lenses for various things, etc). The camera is vital, and is far more enjoyable as compared to optical observations (at least for me).
Planetary you just want good optics, great seeing, and maybe a webcam.
If you live in an area with a lot of light pollution, you're going to be running filters. So a large aperture will help offset that when you aren't driving off to a dark sky site. You want the largest aperture with the best optics you can afford/set up. I have a 14 inch on a dyi mount out in the backyard in a shed that's rigged up to run everything. I would never think about dragging that tube and a motorized mount out to set up somewhere. (I would probably never use it if I had to set it up each time!) A SCT scope is your best bet for a jack of all trades, and smaller set up. They can be a pain to get accurately tracking objects. A 8-10 inch tube would probably be the max I would feel comfortable enough to set up somewhere on my own.
As far as cameras, I have a MallinCam and ATIK camera. The ATIK is for deep space mostly, the MC is when I want to look at pretty video of planets.