get yourself into a cycle shop and try some on. I was looking at getting a pair for a really long ride, but after trying on a few at
Evans, stuck to shorts.
I'm another well upholstered woman, but found when I seemed to have the right size, the straps were digging into my shoulders. As I hadn't had problems with shorts up to then, decided to stick with what works. Plus I had to carry spares with me, so smaller was definitely better.
The stripping off is inconvenient even if you have a cubicle. But if you are doing something like the
Dunwich Dynamo, I'd suggest not drinking any water :-) Actually, I managed that ride without a comfort break, even in shorts. Pee shyness is a terrible curse.