It doesn't seem like there are any Hummer limos in the state of Maine. Has your friend seen any around that just aren't listed on the interent?

Be warned that if you settle for a standard hummer, it may look big but they really will only hold 4 people. There is no bench seat to cram more people in.

The HML (hummer mailing list) is pretty big group of hummer enthusiasts online, and they might know more.

Matthew