Doh, but if you want to change an order, phone them up tomorrow morning, I've actually phoned scan about 10min after ordering to change an item and add one on, and they were happy to help.
EDIT: I did mention the sharkoon golfball fans, just didn't link them as I have no direct experience of them, a friend of mine used them to replace the tricool fans in her antec p182 case & a 2000rpm one on her Thermaltake ultra 120 extreme cooler, she love them, but i've never heard them or had one to compair the air output with other fans.
Quick note on the zalman fan controller, it connects to 6 fans via cables aprox 20cm long, ending in 3pin connectors, the first 2 also have a 2nd cable that you can plug into a fan header on the motherboard so you can monitor the fan speed.
It also requires 1 molex connector for power. (just to let you know)
One other thing to note is LED fans, the led's are powered by the voltage, so reduceing there speed by a fan controller also reduces the brightness, not by a great amount but you do see it as you adjust the fan.
Nice idea on trying out different fans
I've found front fans are always louder for the asic reason that they are closer to you and in a direct line.
e.g. I've got a sharkoon 120mm power fan at the back of my case and an Akasa 120mm blue LED fan at the front, when side by side turned down to min on the zalman fan controller the Akasa is more quiet, but it the case the Akasa is louder (only when both are set to min, turn it up to max and that sharkoon power fan drowns everything out)
That said it does sound like the square grill on your front fan housings are adding to the sound, depending on how thick that steel is you can probably cut out the square grill with a decent pair of wire cutters (or drimmel but only if you have one, don't go and buy one just for this) given that there's a detachable filter and mesh front panel it will not effect the look of the case any
You could also consider cutting out the rear fan grill aswell and replaceing it with one of these
http://www.scan.co.uk/Product.aspx?WebProductId=221413
lol the listing says "no image available" but it's there on the list page
not like I'm trying to encourage to mod your case
