I'm nearing the end of the 40k servitor project I have been working on. At any rate, I think I have all of the stand-alone servitors Games Workshop released finished. I recently finished the metal servitors that accompanied the 'Middlehammer' Techmarine. They were also released in blister packs of two, to go with the Inquisition range.
There are four body variants- two for the heavy weapons and two for close combat. There are two heavy weapon options, and four close combat arm options. It wasn't super easy to find all of the options in this day and age!
I'm up to twenty-five servitors now!