Speak, sure the 1015, along with all other well-designed amplifying equipment, provides transparent reproduction suitable for all speakers; no "matching" is required.
I'd also suggest that you consider QSs for the side surrounds in a 5.1 setup. Also keep in mind that two-channel material doesn't mean that you're not able to make full use of all your speakers. Using processing such as DPLII serves to extract the ambience present(to varying degrees)in two-channel sources which came from directions other than the front, and sends it to the surrounds where it belongs.
