I like this stuff: https://www.amazon.com/gp/product/B01LH1G2IE
It's really flexible and when I rebuild mine I will be using this wire. The wire I used for the first one is not very flexible and with that many wires it causes the servo to really work. 24 gauge is more than enough for this project. You could probably use smaller but should not need to.Flexible wire is the key
The model is already scaled to 110%. This is exactly as I printed it.
Good luck! It's been a real hit at parties and the kids love it.