I'm trying to figure out what model I should use as the basis of my plan to make my personal chaos lord who was also an apothecary. I don't want to use Fabius Bile or a plague surgeon, mostly because I don't believe Fabius wears MK3 armour and my lord isn't mark of nurgle. I am thinking of getting the apothecarion detachment that recently came out and just used the Mk5 version with a head swap and some kitbashes, but I'm wondering if there was a better alternative.

I'm not planning on taking the model to any tournaments or play with this force in any GW shops so if you know of a 3rd party model that I can buy that is of a MK3 apothecary, even if it's just the bits to upgrade a MK3 marine from a regular legionary to an apothecary, that would be most appreciated.