The only way to get true 7.1 surround sound is to have a eight channel speaker setup. Having several tiny drivers inches away from your ears is not going to have the same effect, nor will sound good compared to two large drivers. If you want virtual surround there is free software out there such as Razer surround, or you could buy a sound card and use the virtual surround that comes with it.
I have not tried the Tiamat but from the general consensus the quality seems to align with the rest of their audio products;crap. Good luck having a pair of those as travel headphones, they will break within no time. Headphones from a respectable audio company on the other hand like Audio Technica make their headphones so that they will last.
CS:GO is known to have a mediocre sound engine and using virtual surround likely won't help the situation. To my ears the default audio is much better compared to using surround sound software like Razer Surround.
[video="http
/www.youtube.com/watch?v=tzusBm04RSU&t=4m0s"][/video]
If you had to buy new headphones I would get a pair of open backs like ssddx suggested and use the m50 for travel.