I am with Kyle on this. The -12 offset is the perfect offset for leveled 3rd gens with 17" rims. My XD addicts are 17x9 with -12 offset. Toyo Open Country M/T 35/12.50/17 tires. Also have bilsteins set at 2" in the front. Will be a 6" suspension lift added later this year, so will be interesting to see how they sit then.
Federals appear to be great for the price. I love my Toyo's, except when really cold they are a rough ass ride until they warm up to the road. Once warmed up or when driving in normal temperatures, they are actually a pretty good ride and not loud compared to some M/T's out there.
Heres a side pic from when I first put them on. Note your truck will stay clean for about 2 minutes after washing it lol.