Breasts are far apart, lack upper pole fullness, and they're asymmetrical. Can I go bigger, to 650cc? (photos)

Your breasts naturally sit somewhat fat apart and the base of your breasts cannot be moved. I would suggest not increasing your size, but finding a bra to help push the girls together. Measurements are needed to be sure, but 650 will probably be too large and heavy for your frame and tissue, and just sag with time.

Definitely you would need to be seen in person and examined to best answer this question, but based off of what you have said 650 might be a little too much implant for you. If your base width is actually 13.5cm, the largest implant that fits that (at least among the brands I use) is 580cc. Based off of your description and photos, you could use some capsule work to help push the implants together. The other thing that I consider in cases like yours is adding fat grafting. A little fat grafting to the upper and inner breasts can help create cleavage and upper pole fullness. It will also "make up" the volume you desire while sticking to a slightly smaller implant that what you're requesting.

A large space between the breasts can be caused be a number of different factors. In some women, the breast implant position contributes to the problem. In cases where the breast implants sit too far apart, the situation can be improved with the assistance of an internal bra. The internal bra can be used to modify the position of the implants to support them closer together. This extra support has the dual advantage of improved upper pole fullness.
Sometimes using larger implants actually make the problem worse, because implants that are loo larger in diameter for the chest wall tend to fall towards the armpit (because the round shape to the underlying rib cage).