Hello, I have been an avid user of IEM's for about 2-3 years now. I've gone through some low-end Sennheisers as well as a few Meelectronics models, as well as some random locally found IEM's. Now I'm interested in a pair of under 50$ IEM's which I can find on a site with international shipping. I am mostly interested in them having a sound best fitted for rock music( I'm not talking metal here, mostly classic rock) and maybe some electronic/jazz/classical but about 80% rock. I have some IEM's on my mind but I'd like to see your suggestions here. Also I'd like to know if I'm using the IEM's mostly with a Sansa clip zip filled with Variable OGG's is it worth buying a headphone amp? Does it make any difference besides the volume? Thank you.