Denon AVR-2808ci = that's the one to get.
If you want a multichannel receiver, the Denon AVR-2308ci is an excellent one.
It will also act as an excellent Stereo receiver. And, in the future, when you're ready to expand to a multichannel speaker system, you'll be all set.

And at the discount price, it's a good deal.
I recommend it.
1. The Denon AVR-2308ci will do just fine.
2. There is a Stereo Mode in the 2308 that will allow you to use your sub with it too. No problem there, very easy, you just select that mode, voila.

Stereo sound from your two speakers with your sub, great.
3. No sweat there either, the headphone preamp of that Denon will drive your headphones of high impedance just fine.
4. This is it, the Denon AVR-2808ci. That's the one.
Cheers & Welcome to AH Forums.
And let us know your impresssions on that nice Denon AVR-2808ci after you set it up.
Or if you have any more questions about it, we'll help you, no sweat.
Bob