When I think of Nevada I think dry and rocky. But looking at your picture, and assuming that was in Nevada, it looks wet and grassy. So as far as tires..... I've been a fan of the BFG KO. They just came out with a KO2 but it does not feature a rim protector (yet???). Other popular tires are the Goodyear Duratrac, Cooper A/T3 or Cooper ST something. Decide on if you need an A/T tire or a mud tire.
Another good website/forum is Expedition Portal (not related to the Ford Expedition, rather the act of expeditioning). Using the search function on that site looking for "expedition" to see other Ford Expeditions will be tough but I bet there are a few.
Depending on the type of terrain you want to get into, you may also want to look into sliders, front and rear bumpers, winches and other recovery options. It's a slippery slope.
I spent several days in Utah and Colorado on a trail run and one of the other rigs had a retractable awning. I think it's made by Easi-awn (or some variation of spelling). We'd stop for lunch and deploy the awning. We'd set up camp and deploy the awning. Having portable shade is an awesome thing in certain parts of the country (like Nevada). BUT- you need a roof rock capable of mounting it to. If you decide you want an awning, make sure it's compatible with the rack.
And once you have a nice roof rack, you can carry other stuff on it.
Sorry I'm not much help on lift springs.
