the receiver you mentioned looks to be suitable. it has hdmi inputs and at least 80wpc which is fine for these size speakers. it should be all you need if it has the features you want.
yes, you *can* use other speakers with the 5.1 energy set if you like. the reason i suggested using identical energy speakers is so that they *match* the same sound profile as the rest of your set (so do not sound off/odd/different). there are many people which have a speaker system made up of different speakers (normally the same ones for both the left/right variants of a particular channel set though) and there are people who use larger speakers (floorstanders for instance) for fronts along with smaller speakers for rears. if using two different brand...