5'9" and 8-10 I often buy premium jeans, but have got Levi i-ds in the last year, one skinny and one straight leg pair and they're great. I've found them on offer though so have only paid abiut £40 on them.
Coats... again I tend to buy expensive and have a few so I can rotate iykwim. But my warmest coat is a down filled Barbour gold label, and I will be wearing it this year for the 3rd winter....
Jeans from French Vonnection as well, mind you I don't really need anything more than 34 inch as despite being taller than you most of my height is in my torso and I have relatively short legs for my height.
I really recommend Jack Wills jeans, fantastic quality for the price, I have a pair which are 6 years old and they still look brand new. Can't recommend them enough.
See I just can't get my shoulders into either Barbour or French Connection coats, and the sleeves are a couple of inches too short . Shame as there was a gorgeous navy blue wool coat in FC last year... May be I just have extremely broad shoulders and gorilla-like arms!
And I agree with the M&S jeggings recommendation! Really soft and comfy, too.
Probably too late but I am 5 ft 9 (and a half!) 10 on bottom mostly and 8ish on top. I have bought jeans in Zara- their coated skinnies are great and they have them back in. I also got a fab grey coat in there last week that was plenty long enough. Also, I have recently bought 2/3 pairs of Diesel skinnies- great cut and plenty long enough in the leg. Bit more expensive than some others on high street but worth it in my opinion.
5'11" size 8/10 here - I find Gap's long trouser lengths work well. And Zara's come up super long too. I still need a proper coat though. Have a down filled one from Zara but I think the proportions are a bit off - the waist & pockets are higher than I'd like.