You need to pester
these guys until they do a 22xx series cradle. I'm not sure if they do one quite yet, but a friend has one for his motorbike (39xx series) and it is rock solid.
I am sure you can adapt parts of their aviation/bike/atv line to hold the iPaq...a little diy on another make of cradle to fit a RAM mount might even do the trick.
They are your best bet...
J'bm