C64 PSU

[epicentre]

Hi, I just bought a C64c, but I've heard the PSU is not very reliable (and I'm bidding on it separately, and might not get it). I've also heard that a better option is to modify a C128 PSU and use that instead. I know I have my old Amiga 500 in the attic and it's PSU seems to be the same as C128 one. Is it, can I use it? And is the modification very hard (I only have very basic electronics knowledge)?

I also have my old A500 mouse which looks the same as C64, but I think I've read somewhere that it works a bit different, can that be modified as well?

[SineHacker]

it would be good if you could build your own psu from scratch because the old c64 ones are bulky and nasty. I don't know how though