I ran the calculator and came up with 44DD for you... but I find it to oversize (I have fairly broad shoulders and you look like you may too) and you want it start on the widest hooks, so 42DD is probably a fair starting point. It's trial and error at best IMHO in addition to what you find your fit preference (sung or loose), so if you buy something to try on at home, check out the return policy and process beforehand. I don't know that brand, but I go for features - sturdy underwire, wider from top to bottom (sometimes called smoothing), I like it where the straps can cross in the back, and minimizer design to reduce projection, so a 40DD works for me, but again it varies by design even in the same brand. If you find a design you think you like, you might want to try it in a few sizes for example 42DD, 40DD, 42D and return as needed.
