Hot weather, long sleeve shirts + pants for the tall and skinny

Some brands like Eddie Bauer and LL Bean have "tall" sizes, which I assume you already know about. I'm 6'2" 185 and usually wear L/XL shirts but a medium tall in those brands usually fits me pretty well. For hot weather hiking, I've used standard dress shirts in this size (light colors) and it actually works great even with cotton. If you can find a linen shirt that would be even better (or wool if you want to spend extra). But if you've had zero luck with non-custom dress shirts anyway then I guess that's kinda useless.

There are taller people here who might be able to help out more

I'm 6'5", about 200 lb. Eddie Bauer/First Ascent tops in a Large/Tall fit me perfectly. I don't have much in the way of shoulders, though.

As for pants, there are far, far fewer options in my experience. REI's Sahara zip-offs come in several inseam sizes, the longest of which barely fits me. Beyond that, I have to buy XL, XXL, etc., to get things even close to my ankles. I have NEVER seen rain pants in a tall size. When you see "Big and Tall," know the emphasis is on the "and." :-(

Has pants up to 36 inseam with various waist sizes. I don't fit in anything but sized pants for some of the same reasons you listed.

Todd-

Prepare to have your mind blooooowwwn. I have a pair of these and they fit really well. 6'4" 200lbs here – 36 inseam. Not very UL though.

http://www.cabelas.com/product/Cabelas-GORE-TEX-PacLite-Rainy-River-Pants-Regular/750835.uts

Like Todd, I find pants are almost impossible to find in the right length. Shirts are much easier once you find how the different brands fit. Montbell & Eddie Bauer are two of the best.

Ryan

Short sleeves and shorts for me in hot weather. Problem solved :)

Arc'teryx does "tall" sizes in nearly all their pants models. That said, at 6'4 with a 33 inch waist I am right at the edge of even their tall sizes. Someone slightly longer in the leg with the same waist size would find them too short.