I prefer canti's with the smooth post, as it offers that extra dimension for fitting because not every canti braze-on is perfect, and you need a more adjustable reach than the threaded post type can offer. They can be more challenging to set up . . . but so what. . . learn how to do it and you're fine. My favorites are the Suntour XC Pro and Shimano BR-MC70 . . which are early 80's Deore. These Canti's from Shimano are the King of adjustability, especially for those running 700c wheels on 27" wheeled frames.
There are still some made these days. . . Velo Orange sells some and TRP makes some nice ones too. Shimano and Tektro both have $10 ones if you want inexpensive.