Depends on your work of course.
A single shave horse will not serve all purposes at peak performance. That's why they make a couple of styles.
Start with a shave pony. See if you want one at all.
Its a portable devise that you clamp to a bench or table and stand up to use. Its not as good as a full horse but its quick and cheap to make. And it beats nuthin with a big stick!
I made this one for a couple of brothers in upstate NY who carve Lacrosse sticks.

My buddy Leon makes bows (and arrows) so he needed a long support tongue for working thin whippy stock. Usually a ladder head is most suitable for short stock,
since you have to thread your stock though the ladder. He decided he wanted this design anyway.
You can make a ladder head with nothing but dimensional lumber, which makes it easier.
Everything went well for Leon, until his basketweaving wife and her friends found out you don't have to lay rushs over your thigh to scrape them clean, if you have something else to hold them for you.
Guess what the something else is.
Personally I like a dumbhead horse. Its the most versatile for me.
I got 26 years out of the one you saw on my homepage. It died though and I had to replace it. Here is mine

This is what dumbhead means. Its open to the sides for quickly grabbing long stock but you have the full width jaw across the front for grabbing short stock.

yours Scott