Here are what you need to look for in yarn substitutions, if you get these, you can make any substitution:
-Same quality (i.e. furry, slub, brushed, shiny surface, ribbon, etc)
I usually try to sub a yarn with the same number of plies, but that's really not important.
As long as you stick to that, you'll be fine with any yarn you choose. Also, always knit a swatch to see if your substituted yarn has the right amount of stitch definition, which I doubt would matter for a bib set, but, :shrug: