Need help swapping to DRW

[Storm Chaser]

Just got this truck a couple weeks ago- 78 3/4 ton 2 wheel drive with a flatbed. Just got the engine and tranny installed in this old beater, and decided that I want to convert to a dually. The rear end is taken care of- the axle change is pretty straightforward. My confusion lies in the front...

According to what I found on car-part.com, a local yard has a set of rotors from a 92 GMC HD van (read:short bus) that is supposed to be the same as the rotors on a dually truck. A quick check through Autozone verified the part numbers are the same. Next, I queried autozone for wheel bearings and found out that although the bearings for the van were the same as for a dually truck, they were NOT the same for my 3/4 ton. So, that leads me to believe I need spindles. I typed "1 ton spindles" into car-part.com and that van showed up in my list again. Just for the heck of it, I searched control arms (both upper and lower) and it shows 3/4 ton and 1-ton as using the same parts. The confusion starts when an owner of another local yard swears that those dually van rotors will go with my current spindles, despite the zone's calling for different bearings.

SO, I guess, here are the questions...
1. Am I right to assume that I need the spindles to go with the rotors and that mine won't work?
2. Can someone verify that those van parts are in fact interchangeable with 1-ton drw truck parts?
3. Although I couldn't find a definite answer after hours of searching, are the 1-ton spindles a bolt-on with my current control arms?
4. What about the tie rods? Same from my truck to the new spindle?
5. What do I have to do for the brakes? Are the calipers/mounting brackets the same/different?

The only reason I am stressing over these van parts is that they are in great shape and I'll be getting a pretty good deal on them. Thanks in advance.