I got the drivers from
RTL Fasteners - I believe it was $48 for the set of 8 SAE drivers and $32 for the 5 metric drivers. Strangely enough, the SAE set skips from 7/64" to 9/64" with no 1/8" driver included.
Thanks for the tips on the markings wearing off. Maybe a little thinned epoxy to coat them while they're still fresh?