Hi,
Here in the Netherlands I get my spare blades in a hobby/model/railroad-shop, and my drill-bits preferably in a shop that is called a \'ijzerwarenhandel\' in dutch, uhm, that should translate into english as something like a ironware- or hardwarestore. The drill-bits aren\'t especially meant for modellers, but are ordinary metal-drill-bits ranging from 0.5mm and up; they cost me about 0.50euro. With the blades always make sure to pick a good type of blade, though they may be a bit more expensive, I\'ve hade some rather unpleasant experiences with (partly) braking blades.
Good luck finding your sources!