Don't get the HTR-391 as it doesn't not have a sub level output for a powered sub. It uses speaker level outputs and you won't be able to connect your Denon sub. that's the catch.
Get the Pioneer VSX-822, the HK 1565 or one of the higher up Onkyos if you're willing to take a chance on their reliability.
The Pioneer has networking, Airplay, Pandora and internet radio streaming which is a plus.
I would actually recommend the Denon 1613 as is has better room correction...