I am in the same boat as you! I am a newby myself but I've been reading a lot on the forums and other websites. I ordered my Q701 and should be getting it by Monday. I looked at Astro a50 , Sennheiser PC 363D and Beyerdynamic MMX 300. MMX 300 was too expensive, PC 363D was tempting and Astro would be great if they would sell their Mixamp 5.8 or Pro separately in the US. I ended up getting the Q701 because it got a huge soundstage and I found it was a great bargain for $224.
It is recommended that you use an amp with your Q701. Without an amp, you won't do your Q701 justice! I bought a highly regard portable amp from Meier (2STEPDANCE). I don't know your price range but for $144, O2 by JDS Labs is also very good. You may also check out Total AirHead amp since it's half off at $49! I wouldn't recommend you buy an amp/DAC combo because you wouldn't get the "7.1 surround sound" through 3D audio virtualization like Dolby Headphone or CMSS 3D. The amp/DAC combo would bypass your pc's internal soundcard.
There are Creative Sound Blaster X-Fi, Asus Xonar and Turtle Beach DDS2 but I think they are inferior to stand alone amp. These external game sound cards give you lots of features for your money but it won't sound as great as a dedicated headphone amp. I am not sure what kind of soundcard you have in your pc but I personally would invest a better amp and headphone than a game-oriented equipments. I assume you got the Q701 because you like audiophile grade quality sounds. As for me, I am not just a gamer, I like to listen to high quality music. That's why I bought the Q701. If I was a gamer only, I would be happy with the Logitech G930.
Anyway, I was thinking to get a separate DAC unit so that I could listen to high fidelity music whenever I like. For surround sound experience, I would hooked the amp directly to the PC for games and movies. For high-fidelity music and non-surround sound applications, I would connect the pc to the dac and the dac to the amp and amp to the Q701. The DAC I am leaning toward is CEntrace DACport LX but I am also considering the Audioquest DragonFly. I use my computer for everything especially for movies, games, and music!
I hope I help you somewhat. Let me know what you come up. I could use a few advices... :)
Edited by kaufex - 11/15/12 at 7:08pm