Well they both, a skimmer and refugium, serve the same basic function. That is lowering DOC's in the aquarium. A skimmer, well skims them from the tank- obviously(and will remove a few things macro will not ie. coral toxins). A refugium offers more water volume(dilution is the solution to pollution), as well as a place to grow macro algaes to directly export some DOC's. It will also help boost pod populations, which will help control detritus. It's going to take a good skimmer to rival those combined benefits. Running a good chemical media, like GAC or purigen, w/ the fuge would be a good overall system. Chemical media would aid in removing coral toxins, etc. that the macro can't. A skimmer would be the icing on the cake so to speak IMO.
I had a seaclone, and it just does not compare to the Aqua-C Remora HOB I'm using now. Seaclones do a better job of introducing micro-bubbles than anything else. I literally get more skimmate in a 24 hour period, w/ the remora, than the seaclone would produce in a week, or more, if I was lucky. Invest in something worth your money.