Well I'm not sure what brand you are refering to when you say 6000 or 8000.  I use a Penn Conquer 7000 which is not a large reel compared to other 7000 reels with 30lb braid.   I do a lot of jigging and its good to about 400' deep with current.  If there was not current I could go deeper.  I recently picked up a Battle 8000 for reaching down deeper.  I have caught 40lb Aj s and 30+ pound Kings and countless Blackfin Tunas on that conquer.  In my opinion 25 to 30lbs of drag is more then enough on a kayak because you are going to get pulled anyways.  Also you eventually learn to palm your spool when the fish is making runs to slow them down and I prefer a smaller, lighter reel then a bulky one on the kayak.

Thanks. I was thinking Penn Sargus. For what ever reason I am partial to that model. I'll check out the Conquer also.

~Jeremy