Way too much focus on wool clothing in this thread. All you need to do to come up with a reasonable kit is find out what the climate is like where the rangers patrolled and see real world equivalents and what they wore.
I did like 15 mins of research but the rangers seem to only patrol the land of Eriador, which is located near/around the Shire, Bree and Rivendell. I can't find out exactly what the climate would be like and I don't know much extended Tolkien lore but in every depiction of them and in a few descriptions they are cool hilly, forested areas with ample rain. Rivendell and the Shire are basically idyllic and probably don't have harsh winters or many predators. Safe to say they wouldnt need a magical or even special kit to survive the terrain.
The closest thing irl to a Dunedain I can think of would be an American Longhunter, survivalists that would go into the frontier for months at a time by themselves. I cannot find much info on what they would have worn besides linen clothes. Yeah I know its the wrong time period but honestly the differences in technology might offset the magic in LOTR so its going to be the next best thing. The frocks that Longhunters wear were often made of a mixed cotton and linen material which was considered high quality at the time.
https://www.youtube.com/watch?v=nt0OUVnx-y4https://www.youtube.com/watch?v=oXP2SEmdijU 