I order my truck 2 years ago, but I remember about 60 days for delivery.
I am very happy for going custom build way. Not only I have all the options I desire, but I saved lot of money for not buying what I have no use for.
4x4 not only adds nice amount to the price, but cost you more every day in fuel consumption and lastly it adds 3" to the vehicle height.
Superduties are tall to start and additional 3" with camper makes big difference not only in total height, but also in steps you need for camper.
From what I remember front differential is 600 lb alone.
I opted for LSD as lockable differentials were not available for duallies and the only time I wished for 4x4 was when I was pulling out my boat, while on the sand.
Now I just go to the ramp.