For what it's worth, the load in the bed should not put weight on the front tires, or take it off. If it does, you are loading it wrong. The weight should be centered over the rear axle. If you weigh your truck you will see that the front axle when the truck is empty is pretty close to the axle maximum weight rating. The front of my truck weighs 3,400# and the rear is 2,800#--the front axle rating is 3,800# and the rear is 6,084# (which is governed by tire capacity as each tire is rated at 3,042#). Considering it is a crewcab, with the passengers filling the seats the front end will be at 3,800# without putting anything at all in the bed. All of the cargo load belongs over the rear axle--period.
I really like alaskan155's idea. That idea hinges on finding a chassis-cab axle which puts you 4" per side wider than the ideal 80" (in my opinion, as dually full-sizes are 20% wider than SRW full-sizes) but that could look okay I think.