I Have a SeaCLone Protien Skimmer Forgot what model but it work great
I'm sorry, but they do NOT work great...
as others have mentioned, seaclone skimmers are some of the worst skimmers out there...
I would also ditch the cannister filter for sure... especially since you already have a media reactor.
my suggestion is to get a 20g (24x12x16) tank from petco/petsmart/used as a sump, or a 20 long (30x12x12), this way you will have more room for a real skimmer and possibly a refugium in conjunction with your media reactor for carbon/gfo.
as far as skimmers, look at the SWC 120 cone skimmer, an excellent skimmer that is very productive, with a small footprint, extremely quiet, and inexpensive.
here's a simple sump set-up on my 20g that would be appropriate for your 55g...
the sump is a 20 long, that houses my media reactor, SWC 120 cone skimmer, and eheim 1250 return pump.
simple, efficent, and quiet. I was going to add a refugium, but this small tank doesnt need it, but your 55g would benifit from one.
it can be as simple as a couple pieces of egg crate ziptied in to house the rubble rock and some caluerpa or chaetomorpha with a light on top..