Troy, while you should be fine with the mix as long as all the fronts match, I had an Aperion and Axiom mix also, and while the Aperions are good sounding speakers, Imho they really don't sound near as good as the Axioms, the Aperions are now a 3 channel in the bedroom. You should be fine with any type of sub though.

A computer once beat me at chess, but it was no match for me at kick boxing.