I don't know your size, but I am on the 20 side of 18/20, and I am going for one good pair of work pants from J.Jill. I used to work for the company, and they make a knit stretch pant in wide leg that runs tall even in the regular sizes. I am going XLT b/c I know that will fit for my entire third Tri. It's called the wearever pant. They are really comfy and look professional enough for most workplaces (unless you're required to wear suits). Tip: call a store to order (any store) b/c they will ship it to you for free.
Don't be put off by listed inseams...they tend to run a good inch longer than stated. I probably could get away with the reg (and I have a 34-34 1/2" inseam) but I'll go for the tall for extra room.
Re: **Lopo** and other tall plus girls