Welcome aboard! You certainly came to the right place for help. Not many are 1:6 guys, but there are enough to get you up and running.

Looks like a 1:6 scale 21st Century Toys M5 Stuart. Unfortunately 21C went belly up and getting parts is going to be a task. Best bet is finding people here. Use the search function to get a start and someone with knowledge will come along and point you in the right direction. Man that sucker is big!

Here are some vids of one in action:

http://www.youtube.com/watch?v=_aE71rmON-Q

http://www.youtube.com/watch?v=UMOlMxXiZsc