Hi Mark and Michelle,
Ebay UK have some stuff ....
A MOUSE A MONITOR I think that an ordinary electric kettle lead is all that is required for the power cable. (put a 3amp fuse in the plug though)
My step brother used to be Atari crazy and he is not one for chucking things out. Next time I see him I will see if he has anything you might find useful.
Best to you
Tony