Semi floating axles are what our trucks and most other 1/2 ton trucks use. The semi floating axle is called this because the axle shaft has a wheel flange formed on one end (that your wheel bolts to) and the opposite end is splined to mate with the differential. The axle shaft is retained in the axle housing by a single bearing and retainer at the outer end of the housing (near the rotor on our trucks). The inner end of the axle shaft is supported by the side bearing of the differential. Thus the the axle is doing two jobs at once. 1 it is supporting the weight of the vehicle (with one bearing doing most of the work). 2 it is transmitting torque to the ground through the wheel and tire.
Full floating axles are what many 3/4 ton trucks and 1 ton and larger trucks use. This axle uses a "spindle" at the outer end of the axle housing to support two wheel bearings and a hub that the wheel attaches to. The hub, bearing, and spindle support the weight of the vehicle. The axles shaft is attached the the hub with a bolt flange and is splined on its innerend to mate with the differential. The axle shaft does not carry and of the load of the vehicle it transmits torque only. So it "floats".
I think you are wanting to build a custom axle using a 1 ton center section with your stock outer axle tubes and stock axles. If so Look for a Dana 70u. It is the same spline count and diameter as our axle. You would just need to take your axle tubes out of the stock center section and weld them into the 70's center.