What sort of astrophotography do you want to do, Adrian?
I guess with say an ED80, a HEQ5 and a 350D you could do:
- Fixed tripod widefields (assuming you have lenses with the 350D)
- Short exposure unguided images
- Long exposure widefield images (guided through the ED80)
For lunar / planetary stuff, a larger/longer FL scope and a webcam is probably better.
For long exposure DSOs you'll need to guide - which you won't have the gear for initially but you can build up to that.
Just my 2c... I don't know if it helps your decision, but before you buy is the time to decide what sort of astrophotography you want to do so you buy the right gear to help to develop into it.
Al.