There's a lot about the friendly advice concerning spindles and brakes that I feel like it's important to clear up some bad information.
First of all -- there are basically three different stock spindles: link-pin drum brake, ball-joint drum brake, and ball-joint disc brake. All are different, and all are offered as drop spindles. Pretty much all of our cars have a ball-joint beam, because they're just better. There may be somebody out there with a home-built on a link-pin pan and beam, but they're a rarity.
By the name, you would assume that every disc brake package would use the disc brake spindles, but you'd be wrong. The disc brake spindles are used for the VW 4 lug and late Porsche 5/130 EMPI brakes. Those brakes (as well as the CB rotohub brakes) are VW Ghia knock-offs, and so use the VW Ghia spindles.
Lots and lots of the other (and better) brakes use the drum brake spindles and caliper brackets that bolts to them. I had wide-5s on my car, and the kit was for drum-brake, ball-joint spindles. I redid my brakes last year and went to 5/130 wheels, which meant different brakes. I got a new CB kit with discs that bolt to a hub, rather than the typical heavy one-piece Ghia-style setup. I wanted to use Wilwood Dyna-Lite 4-piston calipers. There's a guy in Canada who makes adapter brackets... for drum-brake spindles. I'm 99% sure Airkewld and KoolStop brakes also use drum-brake spindles.
I've never seen any spindles that weren't drilled for a speedometer cable, or set up for seals. I'm not saying that's never been the case, just that they aren't like that now. A guy can order spindles from pretty much anywhere and they'll likely all come from the same East Asian mud-hut anyhow -- it's just the nature of the hobby now.