Welcome to the Board. You sure seems to know your springs and related tech info...I'm very impressed!!
As for the lug nuts. You don't need expensive units. I have a set of 2nd gen rims on my crewcab, with the center caps, and I used Dorman 611-175 log nuts. If you order them on-line make sure you verify that your getting a box of 10...not one single lug nut. I went through this and was not impressed when I thought I bought 20 lug nuts...for about $20+ dollars...and only 2 lug nuts showed up!!
A front bumper from a 1980-93 will work on the front of your truck. Can guarantee that the bumper brackets are exactly the same...but should be close.