I’m 5’4” 112lbs, 32A. I am choosing between 265 and 295 HP under muscle implants, want to look natural. What should I do?

My best advice: more communication.
It is definitely worth spending more time (prior to the date of surgery) with your plastic surgeon to discuss further.  As you know, it will be important for many reasons, that you feel comfortable that you and your plastic surgeon are on the "same page" prior to proceeding.
One question that might be helpful for you to consider: would you be more disappointed if you are slightly too big or slightly too small after the breast augmentation procedure?
Ultimately, careful communication of your goals (in my practice I prefer the use of goal pictures, direct examination/communication in front of a full-length mirror, in bra sizers, and computer imaging) as well as careful measurements (dimensional planning) will be critical.
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. Have a full discussion and communication regarding your desired goals with your plastic surgeon. This communication will be critical in determining 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. For example, I have found that the use of words such as “natural” or "small C cup” etc means different things to different people and therefore prove unhelpful.
Also, as you know, cup size varies depending on him who makes the bra; therefore, discussing desired cup size may also be inaccurate. Again, the use of computer imaging has been very helpful during the communication process, in our practice.
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, after the use of temporary intraoperative sizers.
I hope this helps. Best wishes for an outcome that you will be very pleased with. 

You need a formal evaluation by a licensed plastic surgeon and expert in breast augmentations to determine what is best for you and your goals.
Proper breast enlargement is not a "cookie-cutter" procedure where the same technique is applied to every patient. Every woman who comes to my practice has unique needs and different goals for her breast augmentation. As a board-certified plastic surgeon, I always listen carefully to each woman's concerns and thoroughly discuss the key points of the procedure. I also take into account their overall height and weight, the size and shape of the underlying chest and ribcage, the tightness and elasticity of the skin, and the amount of natural breast tissue. Prior to the procedure, we discuss and make decisions regarding location of the incision, whether to place the implant under or over the chest muscle, and what type of implant to use (I offer multiple types of silicone gel breast implants, as well as saline implants).
My experience performing thousands of aesthetic breast surgeries in a wide anatomical range of patients enables me to achieve consistently beautiful and natural results that are customized to each patient’s body type and goals. These results are the product of extensive communication, meticulous planning, and skillfully executed surgery.
I suggest consulting with a board-certified plastic surgeon and expert in Breast Augmentation surgeries. - Dr. Cohen

Thank you for your question. The most important factor when sizing implants, is working closely with your surgeon, in person, to find the implant size that gives you the look that you desire. There is a small difference between the two implant sizes. High profile implants tend to give a more "augmented"look. If both implants are high profile, then it's unlikely that you will notice a significant difference between the two implants. I would consider returning to your surgeon's office to discuss further.