Hey, I use the following and both are really quiet.
SWC Skimmers (
http://www.saltwaterconnection.com) - this is my newest one, can't even hear it, and it works very well. I would recommend this brand... For best price go to the website and buy direct, they are in Winnipeg.
Hydor Performer Skimmers - This is my main one, again very quiet and is a 3 pump system. One pump is the water intake and the other 2 are Recirc's. This skimmer has been a top performer for me and blew away my EuroReef model of which I sold. Also, when I had the impellors start making a slight rattle sound, Hydor USA shipped me 2 new ones at NO CHARGE. This is their policy of no charge parts like impellors. So compared to other brands, that is like $70-150 savings per impellor based on brands. This would be my first recommendation based on quality, performance and support.
Here is the link to the manufacturer website:
http://www.hydor.it/prodotti/show/famprod/29/list/11
For hydors, you can get them from Kevin @ Red Coral, he will probably have the best price. You will have to wait to get it, but well worth it.
Hope this helps.