Use Storage blocks. Use the crafting terminal to make a copper block and see which mod's storage block you get. Then program AE to make those blocks and unblock them. That will convert them to a single type, no matter the original types that go in.
Alternately, a Tinker's Smeltery can pour entire blocks that will be guaranteed to break into Tinker's Ingots. And AE can pull the blocks straight from the basin. Plus it works with powders/pulverized ores.
