that search function is really pad. it doesn't even narrow things down and will locate the terms even in common words... anyway.
please address tonal balance, detail (and i mean detail as in detail...throught the range... not as in "oh noez! dis shit gotz lozta highz~!"), isolation, and comfort.
everything considered should be under $150... preferably under $100 to buy or build.
some amps of up to $300 in cost to build or buy may be considered if TRULLY worth the extra dough... but try to keep the recomendations under the first list of requirements.
also, list what phones and IEMs the amps pair well with.