I am also a "small tall". For years I've been wearing ill-fitting shirts and pants because of this. I am 140 pounds and 6'2 . For shirts either I get a medium, and have it be way too wide for me on the shoulders and around my back, or I get a size small shirt and the shoulders and back fit good, but the sleeves and length of the shirt is too short. I'd been buying mediums for years, but started buying smalls now. I'd rather have the shirt fit my shoulders and back and be short as it's more comfortable then big baggy shirts. I've looked up about big and tall stores, and seem they only offer medium tall sizes and above which does me no good
As for pants, It is very difficult to find anything to fit me as well. I have a 29 waist and I need a 32 in the length. That size actually pops up occasionally, but it always seems to be in the skinny jean variety. I am skinny, but my legs aren't super skinny. Like if I wear normal straight cut jeans they are ridiculously baggy on me. But for skinny jeans they are way too tight around my knees and crotch and makes me cranky the moment I put them on ha. Makes me walk like a robot. I've found a few pair of pants that have the legs cut slim, but give a little room for my knees to bend. They aren't jeans though. I found some decent pants at H&M. They are skinny, but aren't jeans material. I found them way too tight around the crotch area though so had to get a size 31 waist and wear them with my belt. The legs are good though. I also managed to find a pair of black dress pants at JC Penny's in 29x 32 that fits me perfect. Besides that though most of my pants don't fit right. It's really annoying.
I recently had some luck in finally finding a sweater that fits me correctly. I'd read online that Forever 21 has stuff that is slim cut that fits tall skinny people well. I managed to find a black hooded sweatshirt in size medium which fits me perfectly. It's long enough because its a medium, and actually isn't baggy on my shoulders and sides because it's cut so slim. It seems like for me this store might have more stuff that will fit my body type correctly, even though it seems a bit embarrassing to buy stuff there since the store caters mostly to women and gay guys it seems. They have some stuff with no logos though, and my sweater is like that.