ok I did not get back to this until now. So I have looked into just buying a component to replace the "poorly designed" part. I in fact did design construct a regulated unit and the part worked very well.
One problem though, the regulator was running hotter then I wanted it to, and I still had to build an RFI can for the part, or use an old can from a stock converter.
The components you have listed here are from what I can see, are not isolated grounds. The requirement is a +10 and -10 volt supply voltage for all of the op amps in the unit. The ground isolation is for the noise factor, and even still there is some motor noise I see on just about every unit, way down in the mud, and you cant hear it in the speakers, but my instrumentation has found it.
I did build the part, but in the end it turned out easier to simply repair the stock part, no heat related issues over time, and the part works.
So there you have it, the deck is repaired exactly as Alpine built it, and from its history, apparently many many people did not seem to think it was to inferior to buy and compete with.
I realize there are "Higher Quality" head units out there, all digital, 24 bit processing, yada yada yada, but this unit has the antiquated analogue outputs, the features that make the unit very easy to operate, and features you cant get from most all other units.
I don't find that I need to enhance, correct, or modify the audio output in any way, other then using the bass and treble controls on the deck, and that for me is just to cool. I tried a number of alpine components, 3347, 3348, fosgate PA2 and NONE of the components made the unit sound any better.
So I will stay with my "old school" unit and be very happy doing so rocking down the road with a Fosgate power 650 amp. My hotrod currently does 130dB of crystal clear audio, that WILL make you go deaf, oh the sound of Eric Clapton unplugged like he is sitting right in front of you playing, good enough for me.