5d Mk II w/ Atomos Ninja 2 CF Card Speed

[mugenstylus1]

Sorry if this is in the wrong forum

I currently have a Canon 5d Mark II, I was planing to do web content video with an attached Atomos Ninja 2 external recorder.
My plan is to use ML only when I record video i was planing on using a 4gb or 8gb CF card to boot ML when I shoot still just use normal Canon firmware.

My questions are:

1. How many of you have done this and could you offer any tips?
2. Does CF Card Speed mater for ML, if I am only using the card to boot and set settings?