Might be a stupid question but i want to change my Commencal Meta AM to 1×10 set up. In their wisdom Commencal decided to opt for a pressfit BB92. I was going to buy a descendant GXP chainset. Am i right in thinking the 83mm option is the correct size for a pressfit BB92?

your gunna buy the grandson of a GXP chainset? 😉
TBH I have no real idea, but would hazard a guess not, as 83mm is normally the domain of DH bikes is it not?

Ive put 1*10 on mine with shimano XT cranks 68/73mm( no need for any spacers ). Hope that helps?

No the 83mm option is for DH you will have to get the sram press fit BB if you want to go with sram the bb92 are for shimano 24mm axle the sram Chainsets reduce on the none drive side so you will need the Sram gpx press-fit BB. The width is the same as external BB they just make the shell wider because the bearings sit inside.