A more pertinent question might be...
Do I really need a modified army vehicle to ferry my kids to and from school and/or bring home the groceries?
I would consider what you need the car for (be honest!), your local traffic conditions (a Hummer in narrow city streets is a bad idea), where you would store The Beast, whether you can afford to run the thing and so on. Compare the fuel usage and efficiency of this vehicle with others in its class and then with the car you actually need. I think you'll find that a Hummer is quite thirsty.
If you still consider a vehicle big enough to ferry Gov. Schwarzenegger around desirable, well... Perhaps you should a have a chat with him about converting yours to biofuels or hydrogen use.
http://en.wikipedia.org/wiki/Arnold_Schwarzenegger#Environmental_record