Don't buy servos from Amazon though: you could get anything.

Spend a few more bucks at e.g. Digikey, eh?

I just assumed they were all terrible, maybe I've just been getting counterfeits this whole time. I'll have to check.

Where do you normally order from to guarantee originals?

Would a counterfeit be a problem for this particular application? Dont they still work?

Awesome project! Newer SG90 are described as a digital servo: http://www.towerpro.com.tw/product/sg90-7/ Should the older analog version (or perhaps a different part entirely?) be used for brachiograph? There's a note in the docs about analog servos being more suitable for this application.