XX1 BB and alternative chainring?

[ALLMTB]

Hello peeps

 

I have the option to fit an XX1 crank to my bike, but I have no experience with SRAM products (only Shimano). 

Which BB should I get? My current frame uses a pressfit BB (Shimano BB91 MTB, Giant Trance).

I think its a BB30 or GXP?

Whats the difference?

 

Also, what are the option for alternative NW chains rings? Anything other than SRAM?

I found this from Race Face....

 

http://www.chainreactioncycles.com/za/en/race-face-direct-mount-sram-narrow-wide-chainring/rp-prod125725

 

Please educate me.

 

Regards

Rene