Basically what you are going to end up doing is pulling the circuits out of the panel, and wiring them into a
dimmer rack. Based on your local
NEC you are going to have to either repull the wires, or if you are allowed to splice in a panel do a hell fo a lot of splicing. You will be pulling all three wires for each plug into the dimmer rack. Each plug will be on a separate dimmer.
ETC makes the industry standard dimmer. And you will have to get an ETC tech to come out to do the inital turn on. They are going to check all the wiring and make sure the rack has been assembled correctly. If you do not do this you will end up voiding the warranty.