As a former Aztek user and current Paasche H / Badger 200 user, I can say that any of your three choices would be preferable to the Aztek.
The Paasche H is actually quite suitable for armor and A/C particularly if you are modleing in the 1/35 and 1/48 scales. In spite of being a single action, it's fine line capability with its No.1 tip is more than adequate at those scales. And for broad coverage, with its No.3 or No.5 tips, it can't be beat. Of the three, it will be the simplest to break down for complete cleaning.
The Badger maybe has a slightly better fine line capability than the Paasche H and theoretically should have slightly better paint atomization although I can't really claim to have obeserved these effects first hand. To my eye, the actual painting performance of the Paasche H vs the Badger 200 seems quite similar. The Badger is a little more work to fully break down, although it really isn't all that bad.
Since you describe your skill as quite ordinary which puts you in the same boat as me, I would be inclined to recommend getting the Paasche H. It's easy to use, easy to clean, and would provide enough performance to exceed your airbrush skill for some time to come. At some time in the future, when you are a master of the airbrush and want to do things that the Paasche cannot deliver you can always pick up a good fine line airbrush like the Badger 100 and relegate the Paasche for base coats and what not.
Andy