I ran a Headshock for a while, got some seals etc from Qwerty Cycles , don't know if they still do them, a short bit of inner tube sealed at both ends is handy to inflate and hold the bearings in place, an adjustable peg spanner or similar is needed, and I made a tubular castellated spanner, not too bad to work on if your confident, I liked the bike it was a flying machine on gravel tracks etc, I reduced the the travel to get the Schrader valve out of the way so I could fit 700c wheels, it would normally run 26, there was one for sale on here last year that I considered, I still keep a look out for a decent hardtail with a Headshock but parts are getting harder to source, USA is probably the best bet.