You're going to have to swap out your receiver for the system to work how you're intending, and since those with multi-channel pre-outs tend to be better than the models without, you might improve your 2-channel listening a decent amount with that move alone. Each company tends to have a "house sound" so since you aren't happy with the sound of your Denon, it's possible you'd prefer another brand. Try looking for a place to buy that will let you audition a few or at least has a decent return policy if possible.
I could be wrong, but I also think you're limited to 5.2.2 atmos setups with that particular receiver so if you're planning 5.1.4, thats another reason to upgrade the receiver first...unfortunately a receiver upgrade is going to cost you more than the tube amps you mentioned, but its really the only way to get everything you're wanting. Goodluck.
I could be wrong, but I also think you're limited to 5.2.2 atmos setups with that particular receiver so if you're planning 5.1.4, thats another reason to upgrade the receiver first...unfortunately a receiver upgrade is going to cost you more than the tube amps you mentioned, but its really the only way to get everything you're wanting. Goodluck.