Nothing wrong with the 70/900 SW scope.
It will be an achromat and show some colour fringing on brighter objects but at f12 it's as good a start as any for visual viewing. Moon, planets, clusters, brighter nebula (M42 eg) will all show. It has a narrow feild of view and is not really suitable for astrophotography although video on moon and planets can be acheived.
Widefeild can be done with just a basic DSLR and an EQ5 mount or a Tracker as has been mentioned earlier. Or you could build a barn door tracker, depnds on your DIY skills and resources.
A minimum longer exposure setup would be an EQ5 and ED80 scope (Apochromat) plus adapters to fit the camera or if you intend to get serious an EQ6. Really serious requires guide cameras and other hardware, laptops etc.
Careful though or you'll slide down the slippery slope into this obse....hobby and your credit card will never recover ...
Like the rest of us ....
