Hi beth, I am taller than you but also quite broad shouldered, boobs quite far apart, size 8-10 and a 32 back.
I had 340 unders 9 weeks ago and am now a 32DD 0r 30E depending on style and brand. I’m really happy with both the size and shape and although they sound big i don’t think they look too big, although buying bra’s is proving a real pain in the back side!