Will the 300cc to 350cc high profile silicone implants look too heavy on me, and will it give me the ideal look I want? (photos)

Recommending implant sizes based on photos alone is a bit tough.  But based on your height, weight and photos anything from 300 to 350 would likely be a reasonable choice.  You should work with your plastic surgeon using sizers as well as 3D computer imaging to help you make your choice.  Best of luck!

Bring some bras in the range of sizes you'd like to be during your consultation. You can then try on sizers that can give you an idea of what size would be most suitable. Based on the info you've provided, the sizes you are thinking about may achieve a natural looking result.Generally, dual plane placement does not substantially make you "lose a few cc's".Please see an experienced board certified plastic surgeon to help you determine what implants would be best for your body.  

Thank you for the question and pictures. Based on your photographs, you are starting at a great place and should have a very nice outcome with breast augmentation surgery.   In regards to more specific advice, despite good intentions, online consultants will not be able to  very helpful.  Careful measurements, dimensional planning, and careful communication will be key.
Generally speaking, the best online advice I can give to ladies who are considering  breast augmentation surgery ( regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully.  Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.  2.  Again, have a full discussion and communication regarding your desired goals with your plastic surgeon. This communication will be critical in determining which operation and/or breast implant size/type/profile will most likely help achieve your goals.
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as “natural” or "C cup" or "top heavy" etc means different things to different people and therefore prove unhelpful.
 Also, as you know, cup size varies depending on who makes the bra; therefore, discussing desired cup  size may also be inaccurate.   Therefore, I ask that my patients not base their communication preoperatively OR  their satisfaction with the outcome of surgery postoperatively, on achieving a specific cup size. The use of computer imaging may be very helpful during this communication phase.
3.  Once you feel you have communicated your goals clearly,  allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals.  Again, in my practice, this decision is usually made during surgery.  The use of temporary intraoperative sizers, viewing the patient's breasts in the upright and supine position, are very helpful during the breast implant selection process.
I hope this, and the attached link, helps.  Best wishes.