A plastic toilet seat? A wood toilet seat? If he finds a plastic toilet seat less physically comfortable than a wood toilet seat, would he willing to put up with a plastic toilet seat if it were cheaper than a wood toilet seat?
Get one with the contact points that rest squarely on the bowl rim. The cheap ones have a design fault that cause problems.
Elongated plastic, quiet-closer with a night light is my choice. Easy to find and once you’re there an easier target for the stand-up user. 
Yabut if you would sit down you could use the bidet feature!