Ratio of the cost of an astrophotography setup and the cost of a Dob is roughly 10:1 for a given telescope aperture. So start with the Dob.
If you get a 6 or 8" you can always put the tube on an EQ mount later - ditto 10 or 12" Dobs, but they will need much heavier and more expensive mounts. Dob is easier and quicker to setup, so many people prefer it for visual astronomy.