If you want a serious answer, bearing in mind i am both very short and rather fat, I buy from everywhere. If it's too long, I take it up or roll it up, if it's too wide, I take it in either by sewing or with safety pins. What people can't see won't hurt them 
. Learning to sew is brilliant for helping 'fix' those less than perfect fashion buys. New look do one of the better ranges for big women, the clothes aren't so garish or too obviously different from their 'normal sized' fashion ranges. The jeans are quite long though but nothing a bit of wundaweb can't sort out. They also, in some stores carry some stuff from specialist plus size designers and while they aren't to my tastes, some of it isn't so bad. Evans dresses everyone like they're middle aged, Yours can be ok but they tend to cater for the bigger end of big and Simply be are ok, especially the partial Joe Browns range they carry. HTH