ESC Motor leads and BEC

I'm about to try using my Mamba Max to run my E-Truggy. I'm using a 4s LiPo setup, anyway what male connector should I put on my motor to mate up with the ESC female? I've got some Team Orion 4MM but they seem a little too big...

and

How do you disable the BEC, I've got an external UBEC I want to use. I've heard you can just clip the red wire and that will do it but I wonder if you guys can confirm that. Someone also told me I don't have to clip it, that I can somehow back it out but I can't see how to do that, any info would be appreciated.

Thanks!

DM