Well, the best way is to experiment. If you have the money, you could buy some from Amazon try them and return them later if you don't like them. Also the For Sale/Trade thread is an excellent way to find amazing deals from friendly, informative and *normally* (I was scammed on my first transaction) users.
http://www.head-fi.org/forum/list/10 I hope you find a pair you like!
But for a general idea, you should check out the major IEM threads:
http://www.head-fi.org/forum/thread/476315/top-tier-universal-iem-comparison-chart-frequency-response-charts-discussion-first-post-updated-often
http://www.head-fi.org/forum/thread/478568/multi-iem-review-63-iems-compared-yuin-ok1-added-05-03
http://www.head-fi.org/forum/thread/386477/review-westone-3-the-ultimate-universal-iem-vs-everything-else-aka-w3-appreciation-thread
Generally, the choices in your range are the following:
Audio-Technica CK100
Audio-Technica CK10
Sennheiser IE8
*Shure SE530
Westone 3
Ultimate Ears Triplefi 10
*Klipsch Custom 3
Klipsch Image X10
*Sleek SA6
Jays Q-Jays
Ortofons EQ7
Monster Turbine Pro Gold
Monster Turbine Pro Copper
EarSonics SM3
JVC FX500
JVC FX700
(Worth mentioning: Head-Direct RE0)
*New updates are coming soon
Audio-Technica CK100
Sennheiser IE8
Shure SE530
Westone 3
Head-Direct RE0
Ultimate Ears Triple.fi 10 Pro
Klipsch Image X10
Sleek SA6-SA7
Ortofons EQ-7
Klipsch Custom 3Audio-Technica CK100
Sennheiser IE8
Shure SE530
Westone 3
Head-Direct RE0
Ultimate Ears Triple.fi 10 Pro
Klipsch Image X10
Sleek SA6-SA7
Ortofons EQ-7
Klipsch Custom 3Audio-Technica CK100
Sennheiser IE8
Shure SE530
Westone 3
Head-Direct RE0
Ultimate Ears Triple.fi 10 Pro
Klipsch Image X10
Sleek SA6-SA7
Ortofons EQ-7
Klipsch Custom 3Audio-Technica CK100
Sennheiser IE8
Shure SE530
Westone 3
Head-Direct RE0
Ultimate Ears Triple.fi 10 Pro
Klipsch Image X10
Sleek SA6-SA7
Ortofons EQ-7
Klipsch Custom 3
Audio-Technica CK100
Sennheiser IE8
Shure SE530
Westone 3
Head-Direct RE0
Ultimate Ears Triple.fi 10 Pro
Klipsch Image X10
Sleek SA6-SA7
Ortofons EQ-7
Klipsch Custom 3
Audio-Technica CK100
Sennheiser IE8
Shure SE530
Westone 3
Head-Direct RE0
Ultimate Ears Triple.fi 10 Pro
Klipsch Image X10
Sleek SA6-SA7
Ortofons EQ-7
Klipsch Custom 3