I would go with 2 separate setups rather than tryting to make one do both things - it will always be a compromise - and probably more expensive in the end as well.
A big dob will give you great DSO views, as well as the ability to image the planets and the moon. Start with 12" and go from there. You will get something 2nd hand that will knock your socks off, and still leave money in the kitty to put towards a decent mount for imaging. For $2200 - you might even get the
12"-er and an
EQ6 and if you still have the ED80(?) you can make a start imaging with some short unguided shots through that.
Cheers
Adam