Implant placement is really a trade-off, and it just depends on which will work best for your body and your ideal appearance. You say you want your breasts to “go together,” and subglandular placement traditionally offers more cleavage. However, you also mention not wanting your implants to sag, and implants placed below the muscle will resist gravity better over the long-term. In either case, a high-profile round implant is more likely to give you the firm, full look I think you want. Find some photos that are similar to the look you want and then bringing them with you to your consultation. From there, your surgeon can conduct a physical exam and make his or her recommendations about the placement that will best meet your goals.