XRAY - Model racing cars

Hello the ones who is reading this post!
I'm new to RC and still waiting for my first kit to arrive (XT8'17). I've got a couple of questions about electronics I cannot find the answers for:

What batteries should be used in nitro truggy (voltage, power)?
What dimensions battery slot in the Radio Case Set (part No. #356004) have?

I've checked some reviews on the Internet and it seems that Arrowmax LiPo 6000mAh 2S TC - 7.4V 130C/65C AM700102 are good, but I have no idea how close this battery is to what is required.

Thanks in advance for your assistance.