If the motherboard is Rev. 4.1 or higher, it supports all AM3+ socket chips which means all FX chips. What you need to do is look at the motherboard's QVL (qualified vendor's list) of memory that is tested and guaranteed to work with this motherboard. That doesn't mean memory not on the list won't work, it just means the motherboard maker didn't test those non-listed memory modules.
Also buy memory in a kit (2x, 4x) than separately to minimize errors as even the same exact model of memory made at different periods and not at the same time can cause errors (differences in silicon, the memory maker changing the memory chip module OEM over time, etc.).