Follow-Up Question: 385cc or 415cc? What is full profile?

Profile terminology will vary from one manufacturer to the next. The terminology matters less than the correlate dimensional measures.
As one goes up in profile the footprint or BWD of the device will shrink and the projection will increase for a given volume. I have found that full profile Allergan implants correlate closely with high profile Mentor implants. These devices exhibit higher projection than similarly sized moderate (+)/moderate profile devices. Ultra high profile is simply the next step upwards in projection.
Patients are encouraged to stay within the boundaries defined by their BWD. This is the best way to avoid the dreaded "fake" look. I generally recommend that patients with smaller frames who are seeking more than a modest augmentation consider a higher profile device.The higher profile device will impart greater projection and thus a less subtle result but will allow for a more significant augmentation than a similarly sized Mod/Mod+. Thus, the ultimate question is one of volume. Is the volume you can achieve via a similarly sized Mod + profile implant adequate to reach your desired goals? If not, a HP will afford you more volume at the cost of subtlety.
The difference between higher and lower profiles for a given volume is projection and for a given width is volume (with the high profile implant being greater in both scenarios). The moderate plus is the most commonly used profile in my practice. It allows for the most reasonable volume in given BWD. In my practice, low profile implants are the least commonly used (widest and flattest). I will typically reserve high profile devices for smaller framed individuals or those seeking a less subtle more dramatic change (the opposite of natural). 
Smaller framed patients tend to prefer HP implants as their BWD can be restrictive with regards to volume. An HP implant will provide greater volume in the same BWD footprint. But remember "natural" while difficult to define often implies a good match between frame, volume and projection. If the goal is natural more conservative sizing/volumes are recommended.
In general, the difference between a moderate and Mod (+), in reality, is very small (on the order of millimeters). Anecdotally, most feel that moderate profile devices are too flat. In my practice, I generally classify profile based upon patient preference. A higher profile provides a more dramatic look (size for size) vs. a moderate/moderate + profile which is relatively more subtle and understated. That being said the vast majority of patients will select a moderate + profile device.
With regards to your specific question, full profile implant will be narrower size for size than it's moderate counterpart. It will also project more and be less subtle. However, I would not struggle over 30 cc as this will make a subtle difference at best.  
In my opinion, the key to a "natural" look is conservative sizing with an eye towards anatomy and frame. Smaller framed individuals by "nature" do not typically have very large breasts. The value of a higher profile device is allowing a smaller framed patient to achieve a greater volume without overstepping the bounds of the BWD.
As always, discuss your concerns with a board certified plastic surgeon (ABPS).

Thanks for your question. The implants that you are considering are very close in size. I would not worry about going too big. You surgeon will likely approve this increase in size without repeat consultation because the difference between implants is negligible.Profile is a way to describe the width vs projection of an implant. I would trust your PS decision to choose the correct profile for your frame. Best of luck! 

The implant selection should be based on a combination of your desired size, soft tissue dynamics, breast base diameter and skin elasticity.  I recommend an in-office examination as well as a detailed discussion with a surgeon who you are comfortable with.   Finally, make sure your surgeon is a Double-Board Certified Plastic Surgeon certified by the American Board of Plastic Surgery (ABPS), a member of the American Society of Plastic Surgery (ASPS), a member of the American Society of Aesthetic Plastic Surgery (ASAPS), and a fellow of the American College of Surgeons (FACS).Best,Dr. DesaiBeverly Hills Institute for Aesthetic Plastic SurgeryHarvard Educated, Beverly Hills & Miami Beach TrainedDouble Board-Certified, Double Fellowship-Trained Beverly Hills Plastic Surgeon