Don't worry about fidelity then - you'll be deaf soon enough and it won't matter!
And no, I don't mean this as a direct attack;
http://www.innerfidelity.com/content/loud-music-sucks
Anyways, I would pass on the Denon D2000 as it sounds like you're going to use these on the go, and they are not the most durable headphones ever made (and that's my sole gripe with them, sonically they will likely do what you want). The Beyerdynamics are going to stand-up better to prolonged (ab)use, and if those don't suit you, there's a number of DJ cans that might be worth considering (Audio-Technica, Pioneer, and Allen&Heath all come to mind here). Again, they'll survive mobile use better, and still get you bass and enough SPLs to ensure substantial hearing damage.
You might also consider in-ears, as they'll likely provide more isolation (which may let you get away with turning the volume down and sparing your hearing; alternately, they're usually very sensitive and can accelerate the hearing loss process if you really want); there's an ocean of options, and I'm not extremely well versed in all of them. The one set I can absolutely suggest based on your criteria are the Denon AH-C751, which have very good low-end response and are fairly affordable for what they offer. I've read about the Klipsch X10 being a "step up" (and it isn't substantially more money), but I haven't bothered to test them out myself. Might also look at some of the options from UE and Ety; I have the Ety hearing protectors and can tell you they isolate very well, and are quite comfortable - the versions that actually make sound can't be all bad based on that.