As an alternative...the TigerCage offers even more structural impovement than a subframe connector.
http://www.ridetech.com/store/tigercage/
We ran Velocity and the 48 Hour Camaro without subframe connectors. Both cars had over 600hp and 600lb/ft of torque. Both were driven...well, quite hard. No cracking, no panel misalignment. Both cars felt solid and stable, and stayed that way after considerable hard use.
Yes, the TigerCage is considerably more money than a set of subframe connectors, but you also get the added benefit of additional crash protection. Its not ugly either. And it can be bolted in a finished car in a few hours.