Best answer I'm afraid is a question: How well stocked is your LFS
If meds can be purchased easily, I wouldn't bother pro actively buying anything. If their stock of items is not very good and you need to buy online, then I would suggest the basics. Copper, preferabley Cupramine with the corresponding multitest copper kit and either the ammonia alert badge or multitest copper kit and a general gram negative antibiotic like Maracyn II. You will need an appropriate amount of the antibiotic to treat a QT
volume at twice the dose daily for seven days.
There are many other types that could be needed but they treat more specific problem and would normally be a complete waste of money otherwise. Personally I would suggest not getting anything if you have easy access.