I hope this post fits in here as it is about kits.
There seems to be a movement at the moment to sell LDR based passive pre-amp kits, and there seems to be complete ignorance about these Light Dependent Resistor products. A word of warning really needs to be published about LDR based pre-amps. LDRs contain Cadmium gas which is lethal (kidney or liver failure) if eaten or breathed and is a long term serious health (Cancer) risk if just touched on a regular basis. Because of this it is illegal to import or sell these items within the EU as they are not RoHS or WEEE approved, so cannot be given a CE mark. This is true for both kits and built products.