Camellia sinensis varieties grown outdoors in an appropriate zone will reach about 15 feet, but indoors in a pot, around 6 feet. However, all need to be stood outside during the summer months, so if you cannot do this, you're unlikely to have much success with it. Even if you can stand it outside, its not easy to grow indoors - its a bit of a prima donna, reacting badly to the slightest changes in temperature or draughts.
As for the Vinca, do you mean Vinca major or minor, or Catharansus rosea, the Madagascan periwinkle, previously called Vinca, and still commonly called by that name? If you're not sure, the link below should help you decide:
The next link is somewhat confusing - it talks about growing vinca 'vines' indoors, but the vinca its referring to is actually Catharansus roseus, not V. major or V. minor. I know this because V. major/minor do not require warm temperatures, they're hardy, sprawling, messy growing, evergreen perennials which grow outdoors and produce blue flowers in early spring, then stop flowering until the following spring. That said, the article gives instructions as to how to grow Catharansus indoors as a houseplant, so its useful for that