[Ideas for a replacement PSU?]

i think you can go to this page
http://www.echoaudio.com/forum/
maybe there are lots of people who can share their ideas with youll ;)

[eletronic simulation]

maybe you can download some trial version like proteus (schematic capture,simulation, and PCB design + 3D output view...)
;)  ;)  ;)

[Where to ground on a PCB?]

we normally connect the ground (low side) to the negative supply, (only if positive power +, and ground "gnd." , are specified in you're schematic diagram, but, if the schematic diagram tells you that, " +, gnd, -", it means you are going to use a power supply with positive,ground,and negative supply...


hope this help!!!
:D :D :D

[Re: sizing pc board artwork]

if you are using Proteus software, you can set your PCB by setting first the work area,(in inches or in cenrimeters)
then just follow the box, and there you have it, :D