After going through the midrange IEMs FLC 8S Hybrid (adjustable),
Westone UM3XR - $323 (smooth),
Sennheiser IE8 - $465 (bass'y),
Audio Technica - ATH-CK10 $299 (flat), Ultimate Ears UE-900 $325 ( meh), Etymotic ER-4P $230 (my first pair), and Ultimate Ears TripleFi 10 $280, looking for my ultimate IEMs, I finally settled on the Noble Kaiser 10Us, $1650 (just right on ultra-low bassiness).
Their 32ohms is a perfect match for the 240mV output...