You want to get a full set of axles from a square body, not a newer truck. If you can get it from one with the same transfer case I would also pull both driveshafts, because the ends are sometimes different from year to year.
4.10 was a common gearing for older 3/4 ton trucks, and it was often used with the 14 bolt FF. I have that setup on my K25 with a TH350, and its a little busy on the highway, but with a 700R4 it should be fine. A 14 bolt FF rear and Dana 44 HD front are a very stout combination. If you already have 16" tires, you can usually buy used 8 bolt 16" steel wheels for about $25 each, and just have the tires moved over.
3.73 gears were also fairly common on 1/2 tons, but some (like yours) had much higher gearing.
Bruce