-Regarding your two amps? Why are you comparing those 2? They are completely different. The 611a can power subs, the other one...well it wont do a good job at it.
-As for subs, I've heard the Perfects in a sealed box, and they can get pretty loud. I havent heard of the VQ :dunno:
Regarding DVC, SVC. With a DVC, you will have more impedance configurations to choose from if you ever decide to add subwoofers or change amps. I would get a DVC, just in case.