The standard office binders have only 2 bolts, in the center. Binder with 4 bolts, evenly spaced will put less strain on the paper sheets.
A alternative can be adhesive rings strengthening the holes.
Binders with 4 rings are undoubtedly better than those Leitzes, the Paterson / Panodia binders were made this way, but in my experience the negatives in their glassine sheets are still heavy enough to cause problems on the long term. Also in my experience, the adhesive rings don't age well, they always fail due to their poor glue, and the colour that develops around them over a few years makes me strongly suspect that they are not chemically safe - which makes them a major no-no for archiving. There may be better quality rings, but unless I have a very good reason to return to vertical storage I will keep doing without them.
Another incidental advantage of horizontal storage, that I discovered when I inherited my late father's old archives, is that it makes it vastly better to store those curled films that look like they'll never want to stay flat no matter what you do. Horizontally, they are a PITA but can be tamed by adding something flat and heavy (eg. a book) over them, and with (considerable) time they even seem to get used to being flat even without the weight. OTOH vertical storage is a never ending nightmare with those. I would never do it with LP's, but negative strips just seem to stay flat better on the long term, when stored horizontally.