Ah, sorry mate, I have been negligent here! I completely forgot.
If you want total silence, you must either use Toroidy.Pl or similar custom toroid manufacturer.
Avoid Airlink. the last three I had from there have a mechanical hum which I hate with a vengeance.
The one in your link is fine but as Alan said some shielding will be required. Loads available in China for £10 and they work really well.