The best thing on the FBQ6200 it's hardwire bypass function. When I tried the eq in my live rig for the first time I had all the faders set to neutral. The sound was much brighter, deeper and richer when the FBQ6200 was bypassed than when it was actually in the signal chain. So in the studio I would absoluteIy not reccomend the thing! I decided to use the FBQ6200 in the monitor amprack. There it looks very cool with the flashing LEDs and all and it can't do to much harm.
On the matter of the sub for your studio setup I cannot help you. I don't use a seperate sub in my studio.
Just wanted to warn you about buying the EQ for this purpose.