Re: what's the best place to find 3s gt's with +3to wof
At the lowest area where greater claws can drop. That should be somewhere in medium-late act 2 nightmare. You can check it with ATMA. You will need a lot of luck to find one, however. It's among the most rare skills which can occur on randomly found claws.
You cannot do much about it with respect to nonmagical items because only elite and half of the exceptional claws can have staffmods at all and they always have a rather high ilvl if dropped by monsters. That means, only tier 3-6 skills are possible with 10% for tier 3 (where wake of fire is in), 20% for tier 4, 50% for tier 5 and 20% for tier 6.
There are a few tricks to produce magical or rare items of exceptional or elite quality while having a low ilvl, but the only one which works with nonmagical items is fixing cracked items with the cube, but an ilvl 1 claw can only have tier 1 or 2 staffmods. Even it it worked, such a claw would have a maximum number of 2 sockets.