I have a pair of those exact same headphones. I also had a Fiio amp and while it was nice (till it broke) even my laptop drives the headphones better. These headphones benefit greatly from more power and they sing well with tube amps/dacs.
The most popular amp/dac combo in your price range is the Schiit Modi/Magni combo. Each one is roughly $120 though. You can start off with the Modi 2 and use your PC to amplify it. I almost bought this combo but I waited till I could get what I really wanted -
Woo Audio 7 Fireflies. Soo good. I know you can't afford it now but you may want to consider it in the future when you have the money. It is soo good. I always heard Beyerdynamic headphones love tube amps but the synergy is just amazing. Sadly there is not much cheaper than the Modi/Magni thats worth it. I think there might be 1 or 2 you can order off of a Chinese site (you can ask on Head-Fi.org) but honestly most stuff is going to cost a lot more. If you can't afford it, stick with onboard sound for now. I did that for like 2-3 years while I lusted for the WA7. It won't have the same sound quality but it will provide enough power to drive them. The Fiio is good when you are traveling somewhere, but I leave my beyers at home now and just use buds on the road.
I too listen to a lot of electronic (melodic dubstep, liquid dnb, ambient, etc.) in addition to a lot of rock.