I wouldn't bother with chris king. Unless you are really hardcore or you are doing trials where you will actually need instant engagement they aren't worth the 500$ cdn you will likely pay. Shimano LX hubs will be fine for the riding you are describing. If you want to add excess strength make it a 36 hole hub and rim setup. IF you do get Chris King be sure to get the metal shell (I forget exactly what it is called) I have many a friend who has destroyed Chris King aluminums.
I wouldn't even recommend tubeless. I live in a very rocky thorny area and never get flats I just have a high quality thick tire with normal tubes.
I like the Rim above recommended. Lighter than mine but still strong. Mavics Rule.