How much power from a BEC?

[Unsullied_Spy]

I have a BL Losi Muggy (used Mike's mount and it fits like a glove!) and I am in need of a steering servo for it. My Hitec 985 might work if I move to the innermost hole on my servo horn, but I still think it will be too weak. I went out in search of a better servo and found THIS. That is a VERY impressive servo, but I'm worried that it will pull too much power out of my BEC and burn it up. I am currently running an MGM 16018 but that is going into my Hyper and I am going to get another ESC for the Muggy (probably MMM, I know they're problematic now but I have confidence CC will get it right) and I just want to make sure I'm not going to burn up ESCs if I go with this servo. It wouldn't be too much of an inconvience to run an Rx pack but that would be just one more battery to charge and eventually replace and I don't want to go with an external BEC right now.