Just note that if you get a large integrated amp that happens to have a stereo preamp output that output might not work at the same time as the speaker outputs. You can use a splitter plug there with one going into the amp stage to the speakers and then run cables to the sub, but the the problem with most if not all these amps is that they have very high output impedance and not a lot of clean power on the headphone output. My Grados sounded like tin cans out of these (due to low impedance load; they get really loud because of the high sensitivity though), and the HD600 just sounded lazy (low voltage output). Honestly what I'd probably do is just use powered monitors so I'd skip having an extra amp for the speakers, unless you blow money on something like that Macintosh or a DAC and the Schiit Ragnarok. Alternately, just have a DAC+HPamp and the NAD D3020 (since it has a dedicated mono subwoofer output) connected to the source at the same time using either an SPDIF switcher, or one on USB and the other on SPDIF or both on USB, then just manually select which audio output device I'd use. Or since the AudioGD NFB-11 has an active preamp then just use longer cables and have an Emotiva speaker power amp positioned off the desk. Alternately, maybe you can fit the AudioGD NFB-28 with Balanced preamp output and any Emotiva with a Balanced input into your budget in case wherever you can position the amp has to run a distance of over 10ft. One other option - try to find someone who can assemble a small Class D fullrange stereo power amp and have them make one for you that has no preamp stage. This way you can get a low noise (albeit higher THD vs Class A amps, though more power; and less switching distortion than Class A/B but with comparable power) amplifier in a very compact chassis that at worst would be slightly taller than an NFB-11.