So after 3 years of being in college without an aquarium (mum killed everything in it when I left for school) I finally brought it back with me after a visit to the rents. Well my filter is having issues and I can't seem to fix it. I have an Aqua Clear 110 on my 36 gal bowfront and when I had it running before I left it was SILENT, however this go around it is super choppy and loud, the filter is now 7yo so I figure it's just getting old and getting loud, it still filters the water perfectly. I've done everything that has been suggested in this situation (taking it apart, cleaning EVERYTHING, clearing the impeller chamber) and still it's super loud. So I've been looking into getting a canister filter since I am planning for this tank to be a show tank and don't really want the filter to be visible anyways. So far I've compared Eheim, Fluva and Marineland canister filters and think I want to go for a Eheim 160G (it's a square looking one). How are these in regards to sound? Ultimately I'm looking to get the quietest filter possible since I have to upgrade anyways, I might as well splurge. I would go for the Eheim classic, but it's not self priming which is just a pain and the Ehaim ecco just doesn't have the water turn over rate I'm looking for. My 110 is at 500 GPH, so I don't want to downgrade from that if I can help it. I've also thought about a DIY wet/dry sump filter, but I don't know how those are in regards to sound and price and if I'd be better off buying a pre-built. So canister filter suggestions based on GPH and sound would be greatly appreciated.

Also, I'm planning for the filter the be installed in my aquarium cabinet, the space available is 13x12x24"