stupid question on hybrid feral spec

So I've decided to try and make this toon a hybrid feral. I kind of already know the answer but I feel like I should ask anyway.. once I'm 85 will I be grinding for 2 sets of leather since bear and cat are gemmed differently? I would assume so since it seems costly to gem dodge/agility constantly to change my role.

Also while I'm on topic.. going hybrid.. when doing cat dps I realize I won't have as great an output.. but will the difference be big enough that I won't ever be accepted for raiding or anything? or put much simpler will I be pulling at least 10-14k dps if I do my rotations right?
http://theincbear.com/hybrid-feral-guide