There are various companies making them and yes some are supposed to be better than others. But at the end of the day it seems different companies get the rights to certain decals from Planetary Pinball for Bally / Williams products.
Phoenix Arcade are one that has a good reputation - check out the info on this link for some general knowledge info that may help you search or determine what you are after. The recent Creature sets were made by these guys and we awesome.
http://www.phoenixarcade.com/printing.htmBay Area Amusements are another good one though use the printing technique but still very good quality - I got a set of of WH20 from them which we very good and postage (US to NSW) was $38 a year ago for these and well packaged.
http://bayareaamusements.com/Merchant2/merchant.mvc?Store_Code=BAA&Screen=PROD&Product_Code=GS-BOP11-1002-50002NGTo put new decals on, takes a bit of elbow grease, and when most people go to the trouble they would sand and prime and sand perfectly flat then paint the base colour of the decals so edges blend in, remember any defects in the cabinet in the process of removing the decals etc will show up in the cabinet under the new decals and pull the quality of the cabinet down.
Hope that helps.
