Hi,
for the A500, you don't need the special PSU, you can easily power it with the floppy connector using and old PC AT PSU (or an ATX if you can put 2 wires :rtfm: ).
A500 is easy to repair. I repared 5 out of 6, and around 8 drives out of 10...
A1000 is bit more complicated, you'll have to buy a electrical desoxyder spray and a teeth brush to clean every circuit and connectors ;-) . This is why I paid mine 42 Euros.. :-D and it works like a charm. You can also adapt an ITX PSU if it's needed.
