I tried sea clones and prisms and returned both. Not happy at all with them. Never tried the aqua c but always here good things about them.
IMO if you have a sump and the water level in your main tank never changes then a hang on skimmer will work best. From my limited experience with skimmers any kind of fluctuation with the water level will throw it off and reduce efficiency. For example you will have some evaporation everyday and then when you top off the skimmer will stop for awhile taking some time to return to normal operation.
My set up is main tank, fuge, sump. I have an in sump skimmer but place it in the fuge. Top offs water changes etc have no effect on the water level in the fuge that the skimmer is operating in and it never skips a beat no matter what kind of tank maintenance I am doing.