Arguably the best suspension kit you can get for a series motor I had thought it had long gone out of production myself..... I might be imaging things, but I seem to remeber Gywn Lewis selling some G2F stuff and maybe QT Services? No harm in phoning them and asking!
i looked at the gon2far links posted earlier and it looks like there are really quite a few modifications that need incorporating to do the job properly, not just fitting revolver shackles
well i've just done a little more reading on these things and they mostly appear to be not recommended on the J**p forums