1.Where do I buy them?
2.How much are they, roughly?
3.How are they installed? (is drilling/rewiring neccesarry?)
4.Where on the guitar do they go?
5.Do they sound like real single coils?

Thanks, all
coil splitting is something you do, not a "thing" in and of itself.

You'll need humbucker pickups that have a hot and ground for each coil (four conductor) and at least one push/pull pot. Usually you replace one or more of your normal volume or tone controls with a push/pull pot that acts as a switch. You'll need to re-wire to install them, but they shouldn't require drilling if you've done your homework. The switches should only cost about $10 for one, and then however much you want to spend on pickups. The PRS I have in my profile has coil splitting; the tone knob functions as the switch. The tones are pretty close to Fendery single coil tones, but it also depends on the type of pickup you get -- the closer to vintage they are, the closer to a true Strat or Tele sound you'll get.
Hi, I'm Peter