I favor the use of machines using bearings on the end of the post.
The basic price includes a model produced by Gotoh, which also uses aluminum post.
As an option, I suggest those from Nicolò Alessi that I really like, and invites you to visit his website to discover his different models.
There are also the Waverly (Sloane), Rodgers and others found with web searches.
One must keep in mind that some models may require modifications to the head design of a new guitar for maximum compatibility, so it is preferable to determine his choice as early as possible after ordering of a guitar.
Also, for any guitars, I will be happy to make the purchase and replacement at a competitive price.
Hauser 7 by Nicolò Alessi