As everyone else stated there are tons of sources for wire,hoses..

For Radiator/heater lines I take the vinyl coating off of paperclips and it is pretty close, within a couple of mm's difference. For anodized lines you can use colored beading wire. The diameter of wire based on scale obviously.

Also solder wire is good for brake lines, it bends easily and is fairly cheap.Also you can look in the holiday gift wrapping section, they have a braided nylon line for wrapping that is very close to real braided line.

Hope it helps, have fun..