What shoud be my next plan of action
I would rather not cut the fan grills as I haven't got the tools
Will getting rid of the fan holders and directly screwing the fans to the case help? Or Do I have to bit the bullet and cut off the fan grills. Or is it back to the shop for lower speed papst fans?
1)Ditch those silly plastic holders and mount the fan(s) directly to the case with grommets. You'll have to drill mounting holes though, the holes that are already there aren't in the correct place. So if you don't have a drill you can stop right here.
2)I'd really suggest biting the bullet and cutting away the grill(s). One of those $8USD nibblers will work fine and shouldn't break your wallet.
3)I'm not personally familiar with those Papst fans. I know that the L1A Panaflo at 5V is very quiet. If
you can find them down there at the bottom of the world.
4)Are you sure you need both case fans? This case has such great airflow that I am able to get great cooling with just the back fan. Try turning off the front fan and watch your temps. You can reduce the noise a lot this way because the front fan is right out in front (duh!) and it's noise escapes through the front bezel. Without it things will be quieter.