Okay, I ordered either one set or four sets of anti-rattle springs ... RockAuto makes it very unclear if it's the usual 4 per package and what the minimum qty is, but at least they're cheap, so I'll either have enough or extras. I also ordered two piston seal kits and front brake lines, as those are getting pretty dry rotted. And an extra set of caliper slide pins, just in case I ever lose one... As long as I have to bleed the brakes, I might as well do it all.