Before you do, check out the following:
http://www.landnetusa.com/
http://terraserver.homeadvisor.msn.com/
http://www.terrafly.com/
These have Topo and Photo components and are on-line!
Good Luck and let us know what you do!
Greg
"Getting close to the game is the joy of Bowhunting for me, the harvest is a bonus."

Live 15 ft Python after eating a small Antelope!