I got a 70watt hid conversion off fleabay for my Lightforce Genesis - a reasonably expensive kit from memory but the seller had great feedback.
Has proven to be money well spent - given the lights an enormous boost in output and (as the kit came with a range of adjustment shims) the beam pattern is unaffected too. Had a flogging over corrugations, mud, rivers, etc no dramas.
My advice is too look for a kit with good rep and you should be happy.

