Not so fast regarding PS Audio PPP. I bought one used three years ago for I think $800 and it has been working fine while doing a good job, including for 120watt/ch quite high current integrated. But when the wall current is particularly bad the system does sound like junk, still much better than without it or with an inexpensive old Furman that I have. That said, I heard too that newer PS Audio models are better and much more reliable, but more expensive of course.
In any case, you will want good power cord from the wall to regenerator. Elizabeth's Furutech duplexes should help too but again - money money money.
In any case, you will want good power cord from the wall to regenerator. Elizabeth's Furutech duplexes should help too but again - money money money.