Are my 34D breasts suitable for reduction? I would like them to be a small C or big B. (photos)

BRs which are medically necessary (i.e. you suffer back, shoulder, head, and neck pain with DOCUMENTED medical attention over a period of a YEAR) are typical reasons for a BR.  If I understand your "private, not nhs" annotation, you plan to pay for the surgery yourself rather than seek a predetermination of benefits from your medical insurance provider.
Recommend that you schedule a consultation with a board certified PS who is an expert in BRs to evaluate your medical condition and history, discuss the pros and cons of this surgery as it applies to you, and help you in making a decision regarding reducing the breasts from a D to a small C or big B which appears to be a realistic goal.
Kenneth Hughes, MD, ABPS Board Certified Plastic Surgeon
Los Angeles, CA

Thank you for the question. Based on your description you may be an excellent candidate for breast reduction surgery.  In my practice, I individualize the “timing” of surgery based on a lot of information that is transmitted during the consultation process.
“Typical” patients who present for breast reduction surgery are women who have disproportionately large breasts, causing problems such as neck/back/shoulder discomfort, postural changes, bra strap grooving, skin irritation/rashes under the breasts, and/or difficulty with activities of daily living and/or exercise etc. There may be both physical as well as psychosocial “stress” caused by the disproportionately large breasts.
Reducing breast tissue mass and elevating the breasts on the chest wall tend to improve or alleviate many of the symptoms associated with the disproportionately large breasts.
Patients considering breast reduction surgery should also consider the potential downsides (risks/complications) associated with the procedure as well. Poor scarring, for example may be associated with the procedure.  Additional surgery may be necessary in the short or longer term for a multitude of reasons.
 
 It will be important that you communicate your goals clearly with your plastic surgeon and make sure that you have realistic expectations prior to proceeding with any type of surgery. In regards to breast size desired, also communicate carefully. In my practice the use of goal pictures are helpful in this regard; a discussion of cup size can be confusing and imprecise.   Therefore, I would not suggest that you communicate your goals and/or base your satisfaction with the outcome of surgery on achieving a specific cup size.  I also find that the use of pictures is more helpful than the words “natural” or "proportionate” or "big B, small C cup" etc., which can mean different things to different people.
Many of my patients choose to have enough breast tissue removed to help alleviate symptoms while retaining enough breast tissue to remain proportionate to the remainder of their torso.
I hope this helps.