that link you put up has the bulbs your looking for, the top line , both hps and MH! further down, theres even what looks like a 400w full spectrum HPs....the one thats flshing red and blue...perfect.

just to add, HPs and MH are used in the UK for industrial/warehouse lighting, as they are bright, long life and cheap to run....that could be an alternative cover for buying them

avoid football stadium type lights though, which look like big security lights.