I ended up buying a bunch of metric standoffs from China for a reasonable price. But that left the problem of how to combine metric and imperial hardware -- e.g., the long 8-32 mounting bolts on the Kaiju PT (I have a snubber board that goes between the PT and the DC Fil board, so I can't use the standoffs that come wit the DC Fil). I had one set of 8-32 standoffs that I pilfered from another project, but needed another set. I just discovered the solution and feel dumb for not having figured this out before: re-thread an M4 standoff to 8-32, and vice versa. Works like a charm even with my really cheap tap and die set.
cheers, Derek