If you could i would reccomend stretching the case budget to the corsair 300r:
it has much more room for longer grphics cards and also has silencing rubber grommits for the PSU so will minimise noise and cancel out any vibration from the unit.
on top of that this case comes with removeable dust filters on the intake fans and the PSU so you should get no dust into the system the supplied exhaust fans are also ver quiet too.
- i am NO expert on the matter but having watched and read numerious reviews it seems an extra 10-20 pounds for this case makes a difference in the qaulity you will get being able to fit the largest of graphics cards into this case too is a plus (tool-less aswell for the most part).
as for the fans nactua/corsair/bequiet seem to be the go-to silent fans bear in mind as well that you can mount rubber stands (they simply stick onto the case) where the fans go to minize/stop vibration and you can get these from B&Q/Homebase for about £5 for 50.