Can my body type hold up to 450cc? I am 5'7 and weight 123lbs.

 I recommend an in person consultation with a plastic surgeon to discuss your goals and be measured. After I do this with my patients, we then look at pictures of women with similar measurements with different size breast implants. My patients tell me that this process is very helpful in determining what size breast implant is right for them.
Dr. Ted Eisenberg, Board Certified Plastic Surgeon and Author

Thanks for your inquiry, without measurements and an exam it is hard to advise.  It is not uncommon for a 450 cc implant to be used, so I am unable to comment on the risk of bottoming out that was proposed to you.  Please get a few in person consultations to discuss.