BFG ATs are a good solid performer for the kind of terrain we run. It will also be quiet on the highway for your daily driver and they look cool too I guess...
Go with a 265/75/16 (32" tall), which will require little or no trimming for your X. For a good deal try Costco or Americas tire.
About the 30k service...do it yourself and save a ton of $$$. It's basiacally just replacing fluids and a bunch of checks (all of which are detailed in your user manual). This will also allow you to run synthetic oil if you like.
If you have any cash left over get sliderz! That or give me some $$$.