my suggestin has nothign to do with it, actually. It all depends on how you want to kill people: wanna use a rocket launcehr? Soldeir. Lay a trap of explody awsomeness? Demoman. BURN THE INFIDELS? Pyro. weilding a Bullet-spitting machine of ultimate DEATH? Heavy Weapons Guy. with the Scope of a high-powered rifle from the next town over? Sniper. Setting up a motion-tracking machinegun turrent with 4-barrel missile launcher attachment? Engineer.
As for Acid as a medic, You have a prefered wepon you wanna hold? One of the needleguns, a medigun, or one of the bonesaws?
Also, adding a order of working on them to the post with the list.
UPDATE EDIT: Completion List added to character list. You'll notice there's a large gap between Gothem and Vixy, and the RED Heavy is listed below Vixy. That's cos i intend to do the RED Medic and Heavy in the same image, and becuase i wanna leave the other slots open for when other people(hopefully) sign up. Now i should probably get started on the actual drawing. o_o;