I am short and more than chubby! If you can wear a size 14 then you will be ok in most any brand. I like the Devon Aire , too. They are a good first time breech.
If you want really stretchy and lightweight, look at Boink.
Kerrits are very nice breeches and some have kind of a tummy control cut in front. They have the neatest bootcut breeches, but I would have it all covered up by my half chaps.
On Course make a nice breech. If you are long of torso, it will be good for you. I am SHORT of torso, so the waist was always too high for me.
If you want a really good quality breech, someday when you are rich and famous, the "trainer's choice" are very well made and have real leather seat.
Are you riding hunt seat or dressage? If dressage, you would want to consider full seat . Once you ride in full seat it's hard to go back.