I'm 6'9" / 206cm, and I've struggled my whole life to find clothing that fits, since I'm slim. If we're sharing links, the two I've been buying from lately are https://tallslimtees.com and https://www.2tall.com. The latter has a large selection of knitwear, which I've never found anywhere else, it's been a game changer. (Most tall sizes are both bigger and taller, so they don't fit correctly. These sites sell taller clothing that'sonly taller.)
If you don't mind me asking how do they fit around your shoulder to bicep area? I tend to need to size up a lot not just for height but for space in that area for myself. A lot of more slim fitting stuff fits me nice overall but basically strangle my armpit and surrounding area. I've resorted to an extremely baggie style to get better space around the sleeve, especially on t-shirts.
Everything I've gotten from 2tall has fit a bit differently, some are a bit roomier there and some are a bit more restricting. I have to order two different sizes of each top I get, because some will fit better in the smaller size and some fit better in the larger. Tall Slim Tees has a smaller selection, but their sizing has been much more consistent for me.
I've never had an issue with feeling restricted in the shoulder area like you're saying though, so I'm probably not the best person to judge that, unfortunately.
