I'd strongly recommend making your own characters, it's more fun, more interesting, and generally the point of inquisitor.
Think of something cool, that you like. And create that character, and model.
Or, Alternativly, make the model and see what kind of character you get.
I do a bit of both, I make a concept, build a model to fit that concept, and then create the character that the model is.
With Esienhorn as a Base, and doing only the simplest of conversions, you can achieve alot. Look at the parts you have and see what you fancy. You could remove the scabbared, and pin the staff in it's place. Swap the sword for a pistol, (28mm space marine pistols or ork pistols make great 54mm pistols, even some guard stuff are fine). If you have another 54mm model, try a head swap.
(I don't actually think I've seen a Josef head on a Esienhorn or Visa versa yet, might work).
But prepared to shave, file and green stuff a little.
But, at the end of it, when you have a real unique model, and build the character to go with it, it's awesome.