In regards to the ruined hardware, www.mountainbikecomponents.co.uk
is the place to go.
As for the sts frame itself, check the areas where the aluminium lugs meet the thermoplastic thouroughly, these frames are infamous for breaking around the BB, or if you have an earlier sts frame without the wraparound style headtube, by the headtube. My first sts-1 died there, but i was lucky enough to find a sts-2 to replace it.
As for components, you dont have to fork out a fortune on hydraulic disk brakes, there are cheap ones nowadays that cost as little as cable ones used to, which has more power and better feel than avid cable ones. Personally i always buy hope, i think its worth the extra money.
Regardless, i hope you enjoy the best looking bike ever having been made! Good find!