Well I am a self confessed refractor nut and I actually agree with the other very wise posts. The newt would be a better choice. But the F5 newt will have more edge of field coma and will be harder to collimate properly than a longer focal length.
Here my 2 cents worth...
Astrophotography:
The 6" refractor is excellent for visual work but doesn't quite fit the requirement for most long-ish exposure astrophotography (in my opinion). The false color will show up on long exposures unless you use color filters and refocus for each filter, which is possible but...
If you were dead set keen on photography then an ED 80mm refractor ($599-$899 depending on which brand name is stamped on it) and the second hand GPDX/skysensor or a new Meade LXD75 with Autostar ($1450 with a free 6" newt) would be awesome. You really need a good mount and a good lens.
Deep Sky:
Buy a Dob. Nothing else comes close for $2K.
Half way in between:
The Meade LXD75 8" schmidt-newt is large and coma corrected but at $2200 just out of your price range. The Celestron C8-NGT is a 8" F6 on an EQ4 with lots of special mods to make it more stable is $2170. You could get it if you lived not to far north. The mount doesn't quite tilt enough without replacing one of the pins (I think there was a review in one of the local mags that mentioned this a few issues back).
Also, feel free to buy something completely different ('cause then I might get the skysensor
).