There are plastic covers for Scott album pages sold either by Amos Advantage (which is Scott Publishing) or maybe it's Subway Stamp Shop -- both online. These are not the covers you buy at office supply stores which would be too small to fit Scott pages, but larger clear plastic covers designed for Scott album pages.
As for the "gold standard" in stamp albums, you're going to get some disagreement depending on who you ask. Lindner (with an "e") is a particular type of album that is very different from Lighthouse. Lindner uses clear plastic pages with open strips for holding stamps. The clear pages with the stamps slid into them are backed up by normal-looking album pages with images of stamps on them. Some collectors put a used copy of each stamp on the "normal" page beneath the mint copy in the clear plastic. The whole system, as you can imagine, is pretty elaborate and the resulting weight of each album is something to behold. And because with all these plastic and paper pages, a single volume can't really cover more than a few years, a Lindner album for one country runs to many volumes. I have something like five or six Lindner volumes just for postwar Germany. So your bookshelves are going to be groaning with the weight of the albums and with the many volumes. Compared to a Scott Specialty album, for example, which covers all of postwar Germany in well under a single volume, albums like Lindner are elaborate users of pages and shelf space. SAFE albums are similar.
Also, some of these albums do not cover the entirety of a nation's stamps, concentrating on the postwar era only in some cases. That can be a problem if you're looking to make a general collection. Worth checking on. Publishers like Scott print albums from issue #1 onward.
Lighthouse albums whose pages are especially elegant is often thought of as the top quality album in print today. Lighthouse goes a different route than Lindner, the more normal one of offering albums either with no mounts (you add your own mounts one at a time -- or use stamp hinges) or pages with mounts already attached. In the long run, the latter is more economical even if, in the short run (the purchase price of the pages) the pages with mounts already attached are very, very expensive. You pay a lot now -- or you pay even more over time.
It can get really expensive. A Lighthouse album covering the entirety of a country's stamps from beginning to the present can run upwards of $2000 for popular countries. It's truly astonishing. Hence the popularly of Scott albums which I've always liked.
I use Scott because I like the layout of their pages, the paper they use is very good, and the whole system looks very nice at a small fraction of the cost of the various European-made albums. Price Scott, Lindner, Lighthouse, and Davo albums for the same countries, and Scott will always be the least expensive -- by far. I do buy used Lighthouse and Lindner (and Kabe and Davo and other) albums in auctions and on
ebay. That's mainly how I've ended up with many of the more expensive albums that I would never have bought new. As noted by others, you essentially buy the stamps in the album and then get that volume of the album at no extra charge. But finding each volume you'd require for your collection can get frustrating. Keep that in mind.