Where can I get wheel spacers for my [DSM]?

Most people seem to have them manufactured. Rick Roeske has a simple recipie - cut the outer rim off of an old pair of stock brake rotors. Any machine shop should be able to do this, in addition to machining the remaining spacer down to the required thickness. You can also read Scott Willards description of his wheel spacers.

Using wheel spacers usually requires using longer wheel studs, which may be hard to find. Where can I get [longer/replacement] wheel studs for my [DSM]?