http://www.soundprofessionals.com/cg.../item/SP-TFB-2
I bought these Binaural mics and they work like a charm with my iHP 140.
Binaural mics are stereo mics that are made to fit inside your ear while recording to best simulate what you would hear naturally. They are made to be played back in headphones, the binaural effect isn't as noticeable on regular speakers.
They are your best bet IMHO. I bought the Low Sensitivity, records 17db - 105 DB without the external battery pack. 20DB is the sound of whispers from 5 feet away. 120 DB is the sound of a amplified rock concert.
70 Bucks, well worth the money.