Well, if you aren't doing a restoration, then you can use almost ANY pad holders OR almost any brake pad type.
For example, I decided to put older, Nuovo Record style pads on a Monoplanar caliper that I have because I (arbitrarily) decided it looks better.
You could use the dreaded-by-some-and-disdained-by-others solid block pads ...
I prefer Shimano-type holders because it is easier to remove-and-insert the pads (as long as you have the appropriate Allen Wrench or screwdriver, depending on the particular pad) AND Shimano/-compatible replacement pads are ubiquitous.