Would a something like a Silverstone Grandia GD04 USB 3.0 be more difficult to cool than a standard tower?
Nothing with an i3 and no graphics card is difficult to cool
If you like the look and size of the GD04 -go for it.
I would use a passive (a bit expensive) or a semi-passive PSU. Noctua NH-L9i LP CPU-cooler and one or two more Noctua RPM-fans as side exhaust. Make the fans spin at 400-600 rpm and everything will run very cool and practically silent. Then as Vicotnik points out the noise level will depend on what HDD:s you put in there.