Please Need Advice on Re-Do Size!

[kynchanted]

Hello! I currently have the following implant:
340 CC high profile textured silicone gel by McGhan, 11.5cm diameter and 4.3 cm projection; 7.5 years old
ribcage: 28.75
base diameter: 12 cm
pec msmt: 35 cm (not sure what this is though)
5'4" 124 pounds
Pre-breast augmentation: 34A
Post-breast augmentation: 34B
I now have capsular contracture on one side and have never been happy with the size I got; I wanted a larger size. My implants are also very far apart; I have a 2-3 finger width between my breasts. Oh and I thought they were the cohesive silicone implants when I got them as well. I am a 34B now and was a 34A pre-breast augmentation. I am having a re-do in November and at the PS's office he told me that my pockets were cut too high and too far apart and that a larger diameter implant would help fix the gap some. He uses Allergan Cohesives and suggested a mod +. I tried on his sizers but they were anatomical shaped (which I am not getting, I want rounds). His sizer at 180cc's on top of what I have now put me at a 520cc's which sounds very large. I want to be a full C/small D (I do not want a full D or DD). Will the 520cc get me to that or should I try the 450 cc instead? I am afraid to go too large since I work out and although I like the larger look and I am somewhat hippy so I don't think it would look so bad, I don't want to look completely fake or fat. I am afraid that the 450 cc will not take me to the size I want though either. There is only .5 cm difference in diameter and .2 cm difference in projection between the 450 and 520, so even though the difference sounds like a lot is it really? Please help!
He also told me that I would have to go over the muscle since I am over the muscle already and there could be a chance of the implant doing something weird and not looking right or something if we went under? I thought overs were a common practice but I am seeing now that they are not. I was under the impression that unders were only used for people that didn't have enough breast tissue to begin with?
Would it help to post pics of my before and current sizes?
Thanks for your help!

[kynchanted]

Oh and I am getting Allergan Inspira Soft Touch textured silicone implants. They are only available in Europe and are considered to be the best. They are cohesive and form stable, but are soft to touch; won't leak when cut, and are in Full Projection (the same as HP, I assume).

[gosgirl123]

It seems great!