If desired, for the perfect salt rim you can liquidise or grind sea salt to make it finer, then run a cut slice of lime (or orange) around the outside...
I just read an article (I think on PUNCH website) which pointed me to the tastetequila.com site. Most of these brands you mentioned are listed on their 'additive-free' guide. I think I've seen a few of them at my local go-to shop. But jeez that article made me want to dump the junk tequila I use for cocktail testings. Could be my mind playing tricks, but I can (not not) taste the artificiality of it now. And, no sir, I don't like it.
As you shoud babe, once you taste quality , please don't go back (you prolly won't bc you seem smart but yh , continue the journey , Los Altos region is specially spectacular )