Hi Alex,
The short answer to your questions is "no." You can't get access to the data and it would not be helpful to you anyway. Consider the huge number of check-ins that might occur at a given cell site over a few hours.
Slightly longer answer: We get the information indirectly from the Air Force Rescue Coordination Center (AFRCC http://www.1af.acc.af.mil/units/afrcc/). There are several cell phone forensics experts around the country. AFRCC will get them the data and get them involved early in most searches. Depending on the size of the mission, the Incident Commander or the Planning Section Chief will then be in contact with the cell phone guy. This can be especially useful if a cell phone hit can be correlated with a 1200 radar track, thus tying the missing airplane to the track. Seldom is it that easy, since a seriously missing airplane is probably out in the boonies where radar doesn't see the lowest several thousand feet AGL and/or the cumulogranite limits coverage. But if there is a hit on one site and no hit on the next logical tower, that is a good potential location clue. Unfortunately that can also be misleading due to the spotty airborne coverage provided by horizontally oriented antenna arrays. So the cell stuff is not magic but it is a good tool to have in the tool box.
I am not a fan of relying on consumer-grade electronics to save my butt, but for what you want a SPOT type gadget is probably the way to go. Also, I have read that SPOT et al are getting more formally plugged into the SAR infrastructure, so that is A Good Thing too.