Hi and welcome
I'm not sure there's all that much difference between the different button tags. I was sent a sample pack of Roxan button tags, which looked fine. Equally, our bought in Z's are wearing various other brands which look ok too.
We've been using Shearwell SET tags for our own sheep and are very happy with them. I was initially worried that the breed society info wouldn't fit onto the SET tags properly, but actually it's fine - see attachment for an example.