Are you happy with the current skimmer performance? If so, then don't do it. The pump needs to match the skimmer and even then, some manufactures just get lucky with a pump/body combo and some worth better than others. If you are off 10% with water, air or contact time, the skimmer could suck.
The only really universal skimmer pumps that seem to work in most skimmers are Sicce PSK and Tunze Hydrofoamer, but both are expensive and AC... they are also pretty reliable. You still have to try and match the GPH as much as possible and even adjust the pumps a bit sometimes.
If you want a DC skimmer, then just buy a whole new skimmer and hope that the combo is as good as what you had.
If you are not impressed with the current performance, then you have nothing to lose. For example, I have older EuroReef and some Early RO skimmers with the Sicce PSK pumps. All of these will wax most newer skimmers, but they have been out a while and I have had the chance to figure out which ones happen to work great. Many skimmers have disappeared into the abyss over the years that did not perform as well.
