Ceramic is the low dust option. I put Autozone Duralast Gold on my 2nd gen, seems to stop fine and lifetime warranty (including wear-out) so never have had to buy them again, though if you just want cheaper one-time purchase w/o a lifetime warranty, then I'd look at the major brand ceramics on Rock Auto.
You'll need to look at the state of your rotors to decide if they need replaced. If there are deep(ish) grooves, probably so. Sandpaper isn't really worth the bother, won't do as much as just applying the brakes a time or two. I mean if there is a lip above where the pad travels, I'd use a knotted wire wheel to knock that down but otherwise, you don't do much to surface irregularities that the pads won't do themselves, except to have them machined down on a lathe if there's enough material remaining.
Some auto parts stores will do this but I think the cost may have risen in recent years, probably $15-20 per rotor these days... if any auto parts stores even offers this any more, might still find a mom 'n pop garage that does it.
If the front and back face of the rotors is rusty, where it contacts the wheel, and hub on the other side, or the hub or wheel itself, do sand those down so they all fit flat against each other, and if there was significant rust then I like to put a coating of silicone paste grease or anti-seize on, to retard the rust growing back.
