Anya obviously but are there any other npcs that spawn worth while gear?

I sometimes go to act 2. ive gotten some nice stuff there if you have the patience too.

all the a2 merchants or any ones specifically?

yeah. elzix and fara. you'll be surprised what may pop up from time to time. but it depends on what specifics you are looking for and the type. and yeah, act 5 at anya get's kick ass claws and weps that show up if you got the patience for that too. ive found some sick ass assassin claws from her.