Their prices have gone up some in the recent year but I wholeheartedly recommend Rosa Gallery from Ukraine. They're definitely artist quality. Amazon has them. They're even better than White Nights, which I used to use. I emailed them and found out that they're still operating in spite of the war. I have most of the metal travel sets they offer and I especially love their plastic travel palette which comes with a full set of paints filling it. I found that the plastic travel set can be filled with White Nights, full pans of Sennelier and full pans of Schminke or can be filled out of tubes so I bought more than one. Mine holds a full set of travel brushes, a pencil, eraser, pencil sharpener and a little piece of sponge as well as a small pipette along with the 24 full pans.
Further, Baouhong from Amazon sells a very good 100% cotton paper block that's reasonably priced and each block of smaller sizes holds 20 pages, And then brushes---I decided to try real hair brushes and on Amazon you can get real hair brushes from Fuumuui. I think some of them say Kolinsky sable but I can't swear to that being the hair. All I know is that they're extremely affordable and don't lose hairs. They work really well.
Not to seem off topic here--I forgot to answer whether I think pans or tubes are better. I've used both but definitely prefer pans. Full pans, preferably because the full pans are easier on brushes. I'm not a prolific artist and tubes get dried out and hard to get the paint out of if they sit around. A filled pan will last me forever---long enough for the tubes to get dried sometimes. My first artist quality paints were White Nights and their paint is in full pans so I just kind of got set in my ways with full pans, even though I've seen the more prolific and experienced artists say the tubes are more economical. The lids of tubes get "glued" on, too, and I can't get them open easily so that's another reason I prefer pans.
Besides that, I don't like wasting paint and watercolors can be reactivated on the palette when they dry. The paint is going to dry on the palette anyway so I don't see much use in using color from the tube that's not dry. Pans are so portable for plein air too, and it's so convenient.
Oh and one other point----I live in an RV. It's quite roomy for an RV but still, my space is limited so I only work on small paintings. I might prefer tubes if I lived where I could do bigger works.