I'd go with the mag, everyone I talked to when I was shopping for a return pump said something to the effect of:
Rio's will last about 5 years tops (more like 3 realistically)with proper cleaning, mags will last double that with taking them out and running them in a bucket of vinegar water to get the buildup out once every 3 months or so.
Double the longevity, but just about double the price too, so it only works out if the mag actually DOES last that long...
I got the mag 12 for my return and its quite quiet.
I doubt theres much advice I can give you of all people hehe, but if anything I'd say stay away from CA
(catalina aquarium) gear, seems to be built very cheap.