If you do like Armstrong tool holders, look for holders made by the Clark Tool Co. formerly of Beverly Hills, Ca. The holder that fits 16" lathes takes tool bits from 1/4" square up to 1/2"; the screw that binds the tool bit is on a 45deg. angle and carries a vee block follower, so it holds the bit much more securely than a comparable Armstrong or Williams tool holder, which in the same size accept only 3/8" square bits (only) and maximum. Clark also made adjustable hole cutters with three tool bits; they are great for cutting holes in fairly thin metal, say up to 1/2" in the larger sizes; I found them on E Bay, after having been introduced to them in the shop where I apprenticed.
When I bought my 19" Regal lathe many years ago in the 1980s, It did not come with a round tool post, I bought an Aloris set at the time (they did not seem so expensive back then!) and never got around to making a round tool post for it, but it would be handy occasionally, I think.
I had Aloris tool holders on all the lathes in my shop, from the DA set on my 30 swing American, the CA 19" Regals and a smaller B size set for the 14" Monarch toolroom latheIf they make you money, they are worth the price; having said that, when I picked up my 10"Monarch from the teens or 20s, since I'm not making money, I bought a Chinese set after rediscovering what a pain it is to use the old Armstrong type.
If you have a shaper, the Armstrong or even better the Williams shaper holders are just the thing; they have a swivel head and hold rectangular tool bits for longer life with resharpenings and higher strength. the Armstrong will hold the tool straight, at 45 degrees and 90 degrees either side; the better Williams has a serrated ring under the tool bit and holds the tool in many more positions, both can be used turned forward or backwards, which when used backwards makes it in effect, a hook tool, lessening chatter when taking wide cuts.