I'm in the same boat, never miss leg day, haven't bought a pair of expensive slim fit jeans in years.
I usually wear Kith Mercer 3s but they aren't exactly cheap pants. You can make the leg bottom as wide as a straight leg pant or narrow like a jogger. Twill and stretchy. At 130, not cheap.
Killion "Trackers" might also work (when they are in stock). 54 bucks, zipped leg opening, stretch twill jogger like pants. Own a few pairs and they fit great and are comfortable around the waist/thigh areas. Just have to see when they are in stock via Twitter/IG.
HM jeans, I've been able to get away with sizing up the slim low jeans just fine. Just make sure the jeans have elasticity in them. Those HM Fear of God pants, I've been able to wear them sized up as well. Tried to wear a size 34 and it was like wearing tights, 36 was fine.
Don't worry about length either. You can stack em.