I agree with Geoff, moving from 6" to 8" will not give you a wow! factor in improvement
of the views. But that being said you can pick out quite allot of object with a good 8"
enough to keep you going for a lifetime.

If I were you darren I'd wait and go for a 12" dob, the 6" and 4"ST OTA will be great
for the Balcony. I think you would like the 12" better

Regards,CS