The Blue Mikes work with the iphone and we are currently trialing them. We are really pleased with the results so far here. Here is a link for you http://www.bluemic.com/mikey/
I can't comment on the mic you mention, but I just did a mini review here on audioboo of three mics, using each one in the review. Of those three, the third I tested, the Belkin one, sounds like what you are looking for as not only is its own mic quite good, but it allows you to connect any third party mic to it, from a small mic with a mini-Jack plug all the way to a studio condenser mic via a mixing desk if you really want. I'm not sure how to link to boos here, but if you go to my profile you'll see I only have a few boos up.
Three Mics Tested - Apple, Griffin, and Belkin.
I think that links to a boo?
http://shop.brando.com.hk/flexible-mini-capsule-microphone-for-iphone-3g-s_p03552c0202d033.html