(Insert funny hello message here)
Hello from Australia!
I have already got a laptop, eGPU enclosure and power supply ready and waiting for a single cable to arrive in the mail, once that arrives you can be sure to see my eGPU build guide, all of the (many) problems I have faced and how I have either dealt with or temporarily ignored every single one
Good luck with your build! (by the by, your Macbook uses the same CPU as does my Lenovo X220T).
Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts