Good choice on the HE-400's, it is also very good at your genres. I'd sya they do best at jazz and instrumental, but also very good on rock & reggae. I own the HE-500, which is better to me, but also way more expensive.
Funny nobody brought up grado, especially for rock?
You should know that the HE-400 does benefit a lot from a better amp despite its low impedance. My new tube amp has made the HE-400 as well as the HE-500 sing. I COULD be satisfied with the HE-400 and a proper amp, but not the HE-500 and a mediocre amp (for example the fiio e17 that i own). It just seems underpowered COMPARED to when it is properly amped.