I agree with this, tires are THE most important. After i excavated my driveway, I tried going up the dirt incline on my stock rubber with no luck. But after I switched over to my BFG MTs, she walked right up there with barely a tap of the gas.
I wouldn't put protection next if you're mainly going to do the mud thing. A moderate lift is the way to go. That way you can get larger tires to get even more clearance.
My $.02
Brian