Why do you wanna extend, I think you should apply for extension only for very valid reason.Recently I have seen and heard many cases that have been denied for extension . B1/B2 extension is really tough, unless its a medical emmergency.

Say,If by any chance u get ur case decison after I 94 expires and if no extenson is granted u end up being out of status and visa becomes invalid, u need to reapply for visa, which is almost impossibl.e 

 Good luck with your decision.