550 Cc's High Profile for 5"0 Too Big? Porn Star Look?

Based on your description of breasts not being 'perky'- you should consider a breast lift. The implants you describe are large, and you are short. I'd avoid using such a large implant. In the long run- a breast lift is going to give you a much nicer looking breast than a breast implant placed in  a breast that needs to be lifted, but was not...

550 cc implants in someone of your hight may be a bit on the large size.  However, without seeing you and examining you, it is hard to give specific advice.  Breast implant size really depends on the amount of breast tissue, chest dimensions and breast width.  Additionally, you may need a lift as well and a smaller implant if you are having to put such a large implant to make your breasts perky.  Good luck.