Yea, this is a good plan.
I recently built a stereo 1176 with the DC PSU built on a separate board. I beefed up the smoothing caps, and had two regulator sections for the -Ve supply, one for the audio and one for the lights/relays etc. The two channels were separated by RC smoothing. I just brought the DC in to the 1176 boards from this board and tapped into the +/0/- rails. Works really well and is virtually hum-free!
To be honest, the lowest hum level was obtained after I sat down for a few hours with a big piece of paper and worked out the best grounding method for all the controls. I worked out the best setup for "telescoping shields" (there's a band name :grin: , a Telescopes/Kevin Shields tribute!) and used screened cable for all important audio and control signals.
Mark