I bought a Dorian tool post, but my tool holders are a hodge-podge of whatever was on sale or convenient. I haven't run into any that were unacceptable, though I did invest in some proper grub screws for them since some come with complete garbage. (Much like the garbage that passes for fasteners at the big box stores.)I couldn't justify the cost of US made in order for me to get tooled up to a decent working level. Most of my tool holders are Shars, that I buy when they put them on sale. The only thing I've found poor, on some imports, are the set screws. Easy to buy some dog tip ones and fix that.
GsT