I'm about to transfer my i5 2500k set up into the NZXT Switch 810 and want some additional fans to give me plenty of temperature clearance.
I live in New Zealand so my options are a little limited, along with my budget, but essentially I'm going to be looking for 120mm or 140mm fans, I've selected on our local price comparison website a few which I think are reasonable value here.
Are there any here which you would recommend?
Any you would avoid?
Any others I should consider?
The case fans that you need depend on a few things:
1) what case will they be used in? How many do you have now, and how many can you put in?
2) what is the ambiant room temperature? Does the room have AC to keep the ambient temp below 80*f in the summer?
3) how important is noise? Because just about any cheap fan can blow a lot of air, but to do so quietly is a whole other matter
4) What is your motherboard, and how many fan connectors does it have (you should use these first)? Will these be controlled by a voltage regulator/bios/speedfan, or will they just run at a set speed? What connectors do you require? 2pin, 3pin, 4pin, 5pin, molex?
5) How important are looks? LED? Styled plastic/fins? black/white/clear/tan plastic?
There are several decent fans on the site you gave, but answering the questions above will help narrow down the ones that would work best for your situation. Also, look into Enermax and NZXT brands, they are a little hit and miss, but I have fallen in love with some of the enermax low RPM fans for my quiet editing rig. But they don't push a lot of air so they may not be good for you if it gets warm where you live, or if you cannot put 4-5 of them in your case.