[longtalltechsan]

For me, the foam tips seem to work the best at giving me the best seal and sound.  I guess the silicon tips just don't fit my ear canals very well. 
 
What kind of amp would you suggest?

 

[wmedrz]

The only amp I own is a Fiio E12 and it helps with boost and overall sound quality. Based on that amp I would recommend other Fiio products or something with a built in DAC. One of my regrets is not getting amp/dac combo. There are reviews hereon headfi basically about every amp/dac I look at and may give you better ideas. 
 
http://www.head-fi.org/t/620775/the-sub-200-portable-amps-shootout-13-11-amps-compared/435