One suggestion, perhaps obvious:
Many music stores have display units out where you can put them on and listen to music, so you can see how you like the feel and the sound. Both are somewhat personal, as both are affected by the shape of your head, as well as more vaguely defined characteristics like how you perceive different frequency "bumps," tolerance for weight strapped to your head, etc.
I've used the Audio-Technica ATHM40 for years and years, and they would seem to fit your criteria: the cord is pretty long (and straight), they're a closed-ear design and I guess they're in your price range. There's a newer model now on "top" of them, but since I already have headphones I like, I haven't bothered to try them out. I'm not sure, but they might slide a bit out of your price range anyway.
More general thoughts:
- On the cord-length: most headphones intended for "studio" use have pretty long cords. You can, of course, simply plug in an extension cable without much difficulty.
- Pretty much any fully closed-ear design should provide sufficient isolation for recording, unless you monitor at unhealthily high volumes or are recording a voice or instrument that's very quiet. There are some models with extra isolation, though they're more intended for special situation, I think, like drummers who are more worried about keeping outside sounds out of their ears (i.e. their drums), rather than the other way 'round.
- I don't know anything about DJing, or how its requirements differ. I suppose if it's a loud enough club, you might need drummer-style isolation just to hear the next song well enough to cue it ... though if you're DJing in such a place, you've thrown in the towel on your hearing and can just crank the headphones to the max and go deaf. My ill-informed eye suggests that dramatic color-schemes, strangely "retro" designs and an association with a name hip-hop artists may also be factors in the DJ world.
