Williams. I’ve used Williams sights for a bit. Don’t recall the year but I put them on SP10 the year Remington bought it from Ithaca. Never had an issue and they’ve been on a few guns.
Here’s just a consideration. On a Benelli 20 ga I put the ghost ring sights on em. They’re about like fire sights but the rear end is a peep. It keeps your head down. I actually like the sight better than the reg open irons.