A co-worker of mine has a King Ranch F150. The most remarkable thing about it is that its seats are covered in brown saddle leather, and the inside smells like a tack shop (mmmmmm leather!). It's pretty loaded with gizmos and bells and whistles, and has some King Ranch specific alloy wheels. I think they all come in a two-tone with a limited selection of colors, but I don't know if they're exclusive to the King Ranch line. It's a pretty nice truck, with a 5.4L and 3.73s.
I think the King Ranch itself is in south Texas, but I'm not sure. Texas is a big place, and it's nowhere around here, so....
I agree totally about the Harley truck. I never understood the tie-in. I do like the older generation Harley trucks, with the supercharged 5.4L (kinda like a detuned 4-door Lightning), but the Harley junk was always a turn off for me.