I own a VSS-3 and a VSS-1. The cables are probably going to be your biggest headache, in more ways than one. Cost, and/or availability. There used to be a thread here I think on someone making the cable(s). The connectors are made out of rare metal known as unobtainium. You'll pay dearly.
The control box- I have seen them on an un-named auction site. Be careful, the two lights take different control boxes. And, as I recall, no, you cannot make one work for the other light. Bulbs-----I never really looked for an extra, but I do think they are out there from time to time.