hey Rosey,
with your stats being quite tall with a decent size shoulder width (34a) 400’s wont be too big in my option,
if i was you i would probably look at 450/500, you need them to fit your frame, hav ea look at my friends on insta “myagirl_17.2.17” she was 32a prior and had 400cc partials but shes only like 5’4 and has a smaller shoulders than you witch is why i think slightly bigger would be better suited.
send her a direct message explaining your looking at getting 400cc Partials so she excepts you, as she only wants genuine people looking 😉