There is a better way of finding the right custom newel post for your staircase than searching through catalogs and designs. Not to mention visiting every staircase maker in your area. You can find one that has been salvaged from older buildings that have been set for demolition.
All over the world, in every city, there are older buildings and homes being designated for demolition due to their age. If you want to match the architectural design of your staircase, you can keep a watch out for houses and buildings set for destruction. There are companies called demolition contractors that do the work of destroying them, but before they tear them down, they go in and salvage anything and everything that can be used again. That includes staircases, flooring, light fixtures, and other material that can be salvaged.
They store them in a warehouse until someone comes along who is looking for period material to enhance their home or building. You can find a whole staircase including the newel, if you look around. You can find them in the phone book under antique, junk, or demolition contractors.
You may hear that a dealer specializing in architectural antiques has the exact newel you need for your staircase. You can be assured they are a salvage company and dropped it out of a house or building before it was torn down. You can also ask around at your local business associations to see if they know of any demolition experts that have material from torn down houses or buildings.
Of course, the Internet is loaded with websites full of decorative treasures you might like in your home. Some of them are dated into the 1800s or later and are still in perfect shape. They made them very well back in the olden days. You can find a vintage maple newel with an acorn design, hand carved, too. You can also find a great oak staircase with the full newel posts for the upstairs and entryway included at some of the salvage companies. Of course, they will cost you some money, but not as much if you had them custom made.
Some of the companies want you to email them pictures of the pieces you need. They will ship them right to your front door. If they have the piece you want, but at a price you can not accept, talk to them. Even if you find the price reasonable, you should still try to barter with them. Just on principle. Most of them are bargain hunters and love a good haggle.
Also, if you already live in an older house and find you need to replace the railroads, newels, or a part of the stairs, you can find them from a salvage company. They save a lot of period material from being torn up and thrown away. You can also just look around your local area and keep watch for houses or buildings being torn down. You do not have to be a contractor to go in and tear out a staircase with a custom newel.