I just checked with the parents and they are looking at buying one now and waiting on a couple of quotes. If you want to hang on a bit I can get you all the info.
This is one thing they told me, GlobalStar is better on land and out to sea up to about 100 miles. After that Iridium is better. GlobalStar is also cheaper.
This is who they have rented through and will probably buy through.
http://www.gmpcs-us.com/
Same company as Big-Z.