Convert wrote:I'm interested in the "special" self-centering ones that you find with some cases. They have a small collet around the top where you thread your screw in that is about the same thickness of the motherboard so it "locks" in place. Though I will settle for the "nub" version that protrudes out of the motherboard hole and has no thread option.
If you've found the other forum threads, then you may have found the other suggestions, which seem like your best shot: Take some of the conventional standoffs you already have, screw in a threaded rod with a bit of epoxy so it won't back out later, then cut off the rod at the desired "nub" length and file down the threads and edges. This will go faster if the threaded rod is brass. If you use both a brass standoff and brass threaded rod, you can bond them with solder rather than epoxy.
Or, rather than filing down the threads, you can leave them, and secure the standoff from the top side using a nylon cap nut. Same installation benefit as the nub, but with the security of a screw.