i use a 5/0 gamakatsu offset hook.  Sometimes EWG sometimes not, but i two would go 5/0.  Looks like they have new 6/0 and 7/0 EWG hooks now, im gonna have to try them.

As for the 9 or 10 pack difference, I have never seen it.  maybe it was a typo or something.  I know i bought a pack of lake fork ring fries from bass pro that had a magic marker line over where it said 15 pack and they only put 10 or 12 in a pack now.  Who knows with these bait companies.

http://www.***.com/descpage-OOW.html

Owner Oversize 7/0 for any worm 10" or bigger.

x2 , i only use OWNER OVERSIZED WORM HOOKS in 7/0 , i get so much better hookups with these hooks . i use ole monsters , ss magnums , and of course the best 10'' worm , the Berkeley powerbait powerworm !!!!!

    Exactly!!!!

    This is the perfect hook for giant worms.

http://www.***.com/descpage-OOW.html

Owner Oversize 7/0 for any worm 10" or bigger.

x2 , i only use OWNER OVERSIZED WORM HOOKS in 7/0 , i get so much better hookups with these hooks . i use ole monsters , ss magnums , and of course the best 10'' worm , the Berkeley powerbait powerworm !!!!!

x3, I agree about the Owner's hooks. Not sure about the powerworm being the best 10" worm though  

For 9 to 10 inch worms I like the old school t rig hooks in 4/0

Same style (Offset Round Worm Hook), but I fish Gamakatsu 5/0.

8-)

X3