okay another no BS response...
Fork mounts - Photography. bad ju ju's unless you have some specific equipment namely Feild De Rotators and Wedge Polar mounts. all extra $$$$$$$$.
This is where it becomes more complex part of astro photography. F numbers.
High f# good resolution at high magnification small FOV.
Low f# good resolution at low magnification large FOV.
High f# Planetary scope
Low f# DSO scope
Fork mount - tracking in two different planes generally have stepper motors
Gem - Tracking in a single plane generally have servo motors(somebody correct me if im wrong) that track smoothly
there are other things that you can do to convert from one to the other though from all that i have seen a entry level scope into photography in the dob/solid tube region will give you a good all rounder scope that can be used for visual/photography, without having to sell your family to fund the purchase.
SCT gives great results though is very expensive especially if your going in green. It could be to your detriment, and we all don't want to see that happen.
hope this helps a bit.