people say ipod sound not good, but I actually got an ipod nano for the sound. I brought the creative zen at first but with my westone UM2 I hear very significant hissing (noise) at the low passages of the song. With the ipod it is much better.... I tried quite a couple of brands from sumsung to sony at various shops as the hissing was driving me nuts when I listen to quiet songs. In the end, the ipod was one of the best.... note that the creative zen sounds slightly better with more punch at louderlistening levels but the hissing was the deal breaker as it was very intrusive at times.
The bottomline is, the headphones you are using is very impt. Just audition it in the shops and get one that sounds good to u and easy to use.
For a more budget portable headphone amp, you can look at amps from C+C, GoVibes etc. For higher end amps there are those from Ray Samuel like Hornet & Tomahawk.
The best way to prove to yourself whether if the sound quality will improve for you is to go down to Jaben and audition it yourself. Only you can tell whether is there any difference or not.
Canon 650D|Panasonic LX3 / LX5
50mm f/1.8 | 85mm f/1.8 | 12-24mm f/4 | 28-75mm f/2.8