Hi Anthony and welcome to the empty wallet society
With the EQ6 and NEQ6 mounts the only difference between the two is one has a wider dovetail head to take Vixen sized dovetail rails.
Now, about the ED80.
It is a fantastic imaging scope. Many of us started our DSO imaging with one, and many of us still use them. They are great for DSLR's on DSO's.
The difference is in the Paint finish.
There is a standard ED80 which is painted black from Saxon, black or white from Orion, and some other colours from other companies. Then there is the Skywatcher Pro Range painted Gold and White, then now there is the Black Diamond range which has sparkly paint.
They are ALL the same scope out of the same factory (Synta) just painted in different paint colours.