Re: Scope for 6.8 SPC AR
I concur with what has already been said.
I think the weaver 1-5 tactical FFP, the new sightron 1-7, the SFWA 1-4 or the PST 1-4 would fill your needs quite nicely.
Where you are going to run into problems is that you insist on high magnification and a medium sized objective lens.
When you are talking mid-priced scopes, something has to give and that is usually the quality of glass. This is a case of, you can't have your cake and eat it too. The exit pupil shrinks as the the magnification increases, to compensate, they increase the size of the objective lens. Unless you are willing to spend on top shelf glass, you will need to compromise.
One of teh scopes that meets ALL of your criteria, except price, is the new IOR 3-18x42 illuminated model. Bump your budget up another 700 or so and you can have one.
However, since you asked and damnitt, it's your rifle, the three that most folks are most familiar with here and come closet to your requirements are:
Weaver 3-15 FFP illuminated tactical scope (probably your best choice)
Bushnell 3-12 FFP illuminated tactical (a very, very good choice)
and, intentioanally last:
the viper pst 4-16 ffp tactical (I am not impressed with the glass on the ONE that I have seen)
Vortex also makes hunting specific scopes that fit the bill, as does weaver, burris, bushnell etc...