Do I need one? I don't think so, however, If I were to get one, which would be a good choice?
ZO2 or E17?
I'm into EDM, classical, pop, country-pop, rap....
I'd stay away from the E17 unless your source allows digital out. If you have a computer as your source, you can use the E17's DAC function-if you are using just about anything else (iPhone, etc) you would have to use the E17 as an amp only-so if you don't use a computer, don't waste money on a DAC you won't use.
I'm sure, just pointing out that if he wouldn't use the DAC, there are better amps to be had for ~$150.