Headphones that scale well with a good amp in $200-300 range

[Sonido]

I'm looking for headphones that really improve if you have a good amp. I recently ordered the Bottlehead Crack and am looking for modestly priced headphones that will really take advantage of this amp. Probably need to be higher impedance. I have the Sennheiser HD598, but it's lower impedance and doesn't benefit too much from an amp. So far I've been looking at the Beyerdynamic DT-880 600 ohms and HD600. Leaning towards the Beyerdynamics cuz I already have Sennheisers, maybe try something different. Any recommendations?
 
Things I'm looking for:
- Wide soundstage
- Smooth bass, punchy, but not overbearing
- Depth to sound, full-bodied
- Non-fatiguing
- Fast as in plays well with fast dynamic music
 
Thanks.

 

[PurpleAngel]

The Sennheiser HD598 might improve it's audio quality hooked up to the Bottleneck amplifier.
When the Bottleneck arrives, test the HD598 with it.
My HD558s sound great plugged into my A/V receiver.
 
 
I do own the DT880 Premium 600-Ohm, got it used (well broken in) and it does sound sweet with music audio.
 
What are you using for an audio source?
What DAC do you have?

 

[Sonido]

DAC I'll likely be using is the Firestone Audio Spitfire HD via USB. Right now I have it hooked up via optical to my TV with O2 amp, but I'm probably just gonna get a cheap Fiio D3 for my TV setup since I found while gaming or watching movies, you pay a lot less attention to the sound.