Hi Mark. In hopes you'll one day soon produce a wondrous line of collectables, I offer the following.
The pro tank along with just about all clearomizers have a 510 connection. It's a M7x0.5 simple thread. The thread on the clearo skirt is M12x0.5. That's the ego drop cone thread.
The most usual batteries are the 18xxx series. The 18 is the nominal diameter in mm, here 18 mm diameter. The xxx is the length in tenths of millimeters. Thus, the 18350 is 35 mm long. The other common sizes are 18500 and 18650, 15 mm longer at each step. That makes it convenient to package a simple inline controller, known by brand name as the Kick by Evolv. It offers variable wattage control without external controls or wiring a fiddly circuit board. Just drop in the 15 mm high package on top of the battery inside the next longer sized battery tube.
Electrically, the tube or body is negative ground, around the periphery of the battery. The positive side ruins through the center of the battery. The atomizers are like that. The batteries are like that. The battery case tends to follow suit. Maybe. The design challenge is to make something compact, durable, good looking, and maintainable. They tend to end up echoing the battery shape with a few notable exceptions. Take a look at the Zenesis Sidewinder for an example.
I own a Zenesis 2, in my mind currently defining the state of the art in construction, design, and surface treatment. Look also at GP Paps and similar for inspiration. Mechanical mods such as these suit a machine shop and small production runs.
The other end of the spectrum is the VV/VW mods. The Vamos, eVics, SVDs, MVPs, and such. They have micro controller based boost regulation for variable voltage/variable wattage firing. The fiddly circuits, wiring, and parts sourcing suits larger, more ambitious production runs. Mass production limits the quality of materials and construction. They can never be in the same league as handcrafted mechanicals. They're not my cup of tea, and maybe not yours either if you're thinking to make something for your own use.
I hope this gets you started. I'm looking forward to see what comes out of your shop.