Quick update:

Took the prototype Sample Rate reducer and added a Blend control:

Check out the video:
http://youtu.be/-A-GNvYRP9U

It works great! 
But I still haven’t solved the power supply issue – it currently needs 2 separate 9v adapters.
(Thats why there’s an extra cable sticking out!)
It’s dead quiet as well – just compare the hissing and squeals in the first videos to the final one.

I’ll add one of these when time permits:
http://www.generalguitargadgets.com/projects/24-power-supplies/137-bipolar-power-supply