moving to peripherals..
you can make any headset 5.1/7.1 with virtual surround. soundcards offer it, some motherboards do, razer software does as well (but isnt as good).
not all play nice with usb dac's though (razer's might, the others likely not).
the adg1 is overpriced though. its based on the ad900x headphones which are $145 but the headset is $225. you're paying an extra $80 for the mic and a cheap amp/dac. might be worth just using the headphones with a modmic with a soundcard given what you seem to be wanting (virtual surround) which would add up to the same price but give you virtual as an option. or, you could use the adg1 with a soundcard via 3.5mm input. your choice there.