I'm considering something like this whenever I build my Jeep. Honestly, do you need the dually tires, though?
What about a 6000 lb trailer axle with 8 on 6.5 spindles. Use same tires on your truck as your trailer, have a spare for the truck and one for the trailer, so you have two tiers that can go either on the truck or trailer, in worst case scenarios.
My flatbed is around 1800 I think, I think you could get that trailer down to about 900-1000 lbs. I think the big savings also are lowing the rig ~8" or so by keeping the 'deck' as low as possible, and getting rid of one axle. Couple that with losing 1000 lbs, and I think it'd be a nice setup.
I would use load equalizing hitch on the truck and a good brake controller.
Note: I think for the two rigs at the top, those are kind of heavy rigs and I'd still want a big 1/2 ton (like a modern F150) or a 3/4 ton. On a 3400lb rig with a 900lb trailer, thats a 4300lb load, that you could do just fine with a 1/2 ton or van. MAybe even something like a Tacoma.
Jsut be real careful with getting the weight balanced and it'd be fine..