Are you talking singles that are very thin box braids or are you talking of the finest of the microbraids? I can tell you from experience that they can do damage. Get them bigger rather than those very tiny ones. Also, make sure you get a good hair.
Synthetic, imho, cuts your natural hair. I'd opt for human hair braids. Oh, and don't let them braid your "baby hairs." Most African braiders think it looks unfinished but it seriously hurts the hairline. You have a lot of weave hair hanging off a little tiny bit of weak edge hair.