24 350cc HP submuscular

So in November 2014 I began researching BA after discovering some of my colleagues had implants which looked very natural. I spoke with them about their experience and figured it was something viable however have been back and forth about whether to do it because I am comfortable with my body already but like other women want to wear those dresses, strapless, backless etc without a bra and swimming costumes without padding! So I decided to book some consultations;
the first was with Transform, I was very unimpressed because the surgeon tried to sow seeds of insecurity but indirectly, i.e. drawing tubular breasts implying I had these, noting and reiterating all imperfections with my breasts and not really having any other method of salesmanship other than trying to make me hate my breasts as they are. I left annoyed and questioning "wow are they really that bad?" I decided to go to another consult and see if they had the same opinion
I then went to The Hospital Group, my patient care co-ordinator Sara Shone was fantastic, very empathic, reassuring and thorough. I explained what had happened with Transform and she was as shocked as I was at what their surgeon had said. So then I met my PS Mr Marcos Sforza who I had researched prior to the consult and was so far impressed with the amount of information online for him (Transform had very little apart from their own bias testimonials). Mr Sforza was fantastic, he made no attempt to highlight the negatives and answered my questions in detail. He was so laid back but in a professional manner and appeared very honest and trustworthy. I then tried on some sizers and decided 350cc looked good for my size however after reading a lot of reviews I'm wondering whether to go bigger, to the 380cc perhaps? Any advice on this would be welcomed!
I left the consult really confident and excited then returned home to tell the BF I would be going ahead! BF has been extremely supportive and will be helping me through recovery :).
Shortly after with an obsessive amount of research I started to panic about capsular contracture as the rates of this vary with some saying up to 25%! I emailed my patient care co-ordinator and she rang me to explain that in all her years working there she had seen a couple douzen and the rate was more like 2%. I hope this is the case because cc would just be devastating after going through all that! She was very reassuring and most of all she was very genuine, I cannot commend her professionalism along with the PS enough!
So I'm still waiting to hear what dates are available for May but hoping for around the 12-15th mark, once I have one booked I will update but in the mean time any words of advice, comments or input would be massively appreciated!

Im wondering whether to go bigger? the number 400 sounds so scary for some reason even though the difference isn't huge. I've read a few reviews say their ps has 5 different sized of implants during the op, I've never been told this is in the UK not sure if it's standard practice?

So people have an idea of what I'm working with, any suggestions given these pictures of what I may be following 350cc under the muscle (possibly fully or partially).