Welcome! Always happy to see another species collector chasing non-TCG items too!
Great variety of items posted so far! I’ll definitely be following your journey 
There are a lot of amazing resources here on this forum. Including what @joponnes linked already, there’s also a pretty much complete list of English code variants here (the Japanese code effort is just starting) and a pretty thorough cameo list, if you choose to include those in your collection too.
The unlimited Japanese variants can be hard to find, but I enjoy the thrill of the hunt. If I have some time to spare, I’ll try to poke around to see if I can spot any on Mercari or something. I’ll send Kabuto/Kabutops non-TCG items your way if I spot anything too.
Look forward to your updates!