Romans, I'm guessing your Xentec system was a Xenon (HID) system? If so, I second it.
I haven't used PIAA but have heard the bulbs burn out frequently and they're not as bright as HID - simply awesome lighting - you'll still need to tweak your lights up about 3 or 4 turns, but it's a no brainer once you see how much output they provide.
First install I did was the 35 watt lights, and they were incredible - with my front end plastics and lights being replaced I'm going to do the 55 watt kit this time.
This place has pretty good prices and has explanations about diff between 35 & 55 watt systems:
http://www.ddmtuning.com/products/DDM_35W_55W_Slim_Ballast_HID_Kit-101-85.html
I've heard good reports of eBay purchases as well and much lower priced, but somehow can't get myself to go there...
-Dennis