The power supply, and PCB update...
Any regulated +/-12Vdc to +/-15Vdc supply can be used. Rod Elliot's P05 design and PCB would work great, but I may end up making my own boards.
It's based on the LM317 and LM337 adjustable regulators. These are said to work better, with lower noise and better regulation than the LM7815/LM7915 fixed regulators. I don't think it really matters for this application; the fixed regulators would work fine, and are easier to assemble on perfboard point to point than the adjustable ones.
Also, I've started laying out the PCB for the preamp itself. This is just a preliminary parts placement diagram, no traces yet.
The volume control will be mounted off board; connections for it will be towards the center of the board. The board will be single sided, making it easier to DIY. The lead spacing for the resistors is 12.5mm so 1/2W's will fit easily...