I would return it. A noise coming from the PSU is a very bad sign.
When you do return it, tell them you want to trade it in for a different kind of PSU entirely. Pay whatever the difference is.
The way to figure out what is a good PSU to get or not is to go on www.newegg.com, go into the PSU section, and then choose whatever wattage range you want (like 600 - 700) and then everything that comes up with an award from Hardware Secrets or JohnnyGuru is on the consider list and everything that doesn't have an award from them is removed from consideration.
Just compare that list with what is available to you where you are shopping at and pick whichever one.