WHen used as a mu follower, the PS is again included in the PS, but still to a large degree isolated...so a High performance PS is still a good idea, and contributes in a positive way to the sound.

On the detail construction of the CCS, there is some benefit to building with a few batteries and the R-C filter on the gate. ONe needs to protect the +/- 20 volt gate-source voltage maximum with a cathode-cathode Zener clamp. The batteries will prefer a low leakage version BZX79C18 would be my preference, though BZX55C18 is not far behind...:)
cheers,
Douglas