Add every specific skin to be made into different units

Howdy, folks. What if I could have a classic battle cruiser skin be a specific unit in a mod? Plus have the default battle cruiser skin be a unit with different stats? I want to make a mod that’s kinda funky! I want to have the firebat from Brood War in the mod. I want to have the siege tanks from Brood War in the mod. I want to work on the Valkire 3D models that people have going and add that too the mod. So yes, in this mod; you will be able to choose 2 types of fire bats; and 2 types of siege tanks, all the Brood War units, and I’m also adding all of the campaign units. What do you all think, please?

But, your question is: How to do it? or Is it a good idea?