the Canon HF M300 seems to meet all your requirements - but the $MSRP... and bhphotovideo appears to have a deal on it
http://www.bhphotovideo.com/c/product/671648-REG/Canon_4357B001_VIXIA_HF_M300_Flash.html
through 1/8/11...
Check the manual
http://gdlp01.c-wss.com/gds/5/0300003135/01/hfm30-m31-m300-nim-en.pdf
Mic input - Page 20, item 6.
IR remote zoom - page 22.
Hopefully your computer and video editor can deal with AVCHD compressed MTS files.
I've been trying for days to find a camera with these features:
1. Small
2. Mic input
3. Wireless or wired remote zoom, or LANC input
4. Under $400
SD or HD does not matter to me. The Canon FS200 comes close, but has no remote zoom. Likewise, I've seen Sony models with the zoom but no mic input. If the camera has a LANC input, I could buy a remote zoom.
Anyone know of one that combines all the above features?
Thanks for any help!
Mark

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic