Yeah I've been building mine slowly since I drove it off the lot brand new in '06. I've got tires, suspension, power adders and dress up stuff in place but now I need to start reinforcing the undecarriage. Rock sliders, UCP & shock skids are next on my list. Fortuately I'm a moderator for the biggest HUMMER forum/Club on the net so I've got lots of great connections for parts and custom aftermarket add-ons. Do you have any places that you take it off road locally? There is a spot in watertown... but I don't know if were supposed to be up there or not.
But there are some pretty fun hills to climb and if it rains there is a massive mud pit. Thank God for M/T's!