Recoloring standard chests sounds like a good start. I initially started with that but switched to custom graphics both so I could learn the API and so it would force me to do real graphics when the mod is ready. If someone opens a PR I won't say no, but otherwise I'll figure out how to make real graphics. I have some interesting ideas for what the chests can look like but need some time to learn Blender and make them look good.
I'm hesitant to add AAI loaders as a dependency. While they do look amazing, the license is really restrictive and I don't want to rely on a project that I can't edit. That being said there is nothing special about network loaders and nothing stopping users from using AAI loaders instead.
Network Tanks will definitely need a new icon, so if I'm making one then I might as well make all 3.