And are not aluminium . . .
As to a quite case, easy, take out all the fans and replace the hard drives with SSD's
there you go silent, even if it is a cheap £15 budget case
All the padding will do nothing if you have a high air flow delta fan in it.
same goes for thermal performance, a £15 case with a couple of delta fans in is going to keep hardware cool, it'll also sound like a jet engine and suck in any close by lose objects.
That said the basic fractal design R3 is very nice
http://www.scan.co.uk/products/fract...r-case-w-o-psu
You may need to add some additional fans, but for an undervolted e6600 and a low end gpu you don't need super cooling at all.
the stock fractal fans are very quite main because the rpm is so low, but that does mean less air flow.
How many hard drives do you want to put in this, personally speaking they are a major source of vibration after fans, getting a case with built in vibration damping (normally grommets on the screws) is much better than trying to damp vibrations of hdd is a cage not designed to have anti-vibration added.