The goal is to get the same gauge that the pattern asks for, with the yarn that you choose. Therefore you want to choose something with similar recommendations so that getting that gauge won't be a major pain. The only way to know is to buy a ball of the yarn and make a gauge swatch or two. You might find that the particular yarn with the right needle size to get the pattern's gauge forms a fabric that is not to your liking. Too loose, too tight, whatever. You can't know for sure until you've used the yarn.
The yarn that you're talking about sounds more like a DK weight yarn, vs. the pattern yarn that sounds likely worsted. It might be too much of a difference, but you won't know for sure until you've tried.
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Ravelry username: HeatherDD
You just try out the yarn you want on size 8s and see if you get pattern gauge. The label gauge mostly indicates what weight the yarn is; I've seen patterns that call for needles a size or two larger than the needles used for the label gauge.