The hardware foundation that you are looking at, will not raise the
performace of the Energy Takes to a higher level > The Fact, that
you stated, the Energy sounded very clean with the Onkyo, is a key
point. A decent receiver with HDMI, can be a good performer.
Do you have any real complaints with your Dayton amp?
If you are looking to get the best bang for the buck, then I would
build around a speaker system and not the hardware system. Then
build around the speakers, if you feel more is needed later. While
the Energy is budget friendly, there are some better options, that
can step-up the sound experience.
Speakers with bigger woofers that can cross-over better (lower) to a
subwoofer, can bring a nice listening experience with better balance
performace. You can also build the 5.1 in sections, depending on the
quality that you desire.
If you wish to analyze all this again, and desire to build around a
different speaker system, and build off the speakers - then what
is the maxium budget that you want to work with? If you want to
go with the way you are thinking now > then I will give you some
more speaker options to consider. You option and choice.