fjt,
I am a PC owner, I have the 7336SP model I got from Lowe's. They sell this model there for about $109, don't about different areas, it may vary. At first I was skeptic about it, scratches, burn the paint, etc etc... I was wrong!! there very easy to use, make the job go quicker and you use less product which helps out in the detailing business.
You would have to do something really really out of this world stupid to mess the paint with this machine. I know I sound like some sales guy for Porter Cable saying just how great it is, lol j/k
Both Spichy and Aaron gave the best links for info about the PC and info on it's pads, backplates, accessories etc etc...
As far as what pads to use with what products you mentioned. I also have Meguiars #7 Show Car Glaze. Good product great shine, can be tempermental to remove if your technique isn't right. There is a thread in the hall of fame forum here at Autopia, it's Called #7 by Mike Phillips or something along those lines. David Bynon is the town mayor here but Mike Phillips is a bigtime detailer and works for Meguiars, Mike originally wrote that thread, very informative.
Pads, IMO, with #7 you have 2 choices here. You can use a foam polishing pad or a foam finishing pad. It's best to match the agressiveness of your product with the pad. Say if your using #7, #7 has no cleaning action, hence the name, show car GLAZE. DACP, you could use with either a polishing pad or a cutting pad. A polishing pad will be the mose versitle pad in your line, correct me if I'm wrong here.
I usually apply paste waxes by hand, and save the liquids for machine applications if need be. Hope this helps,,,,,,91