Well, if you want the easy way, there are some lovely
Elantec chips
(EL2001, EL2002, EL2003, IIRC) that are unity-gain buffers with some
I am
unfamiliar with these chips.
I am not sure if/where you'd find data sheets on
the web, but they
probably exist. But from what I remmeber there are only 4 active
connections -- +12V, Ground, Input, Output.