I don't knit cables, so really can't help you there.
I usually buy yarn and then come across a pattern. Sometimes I see a pattern and then buy the yarn but not often. But I don't knit to a specific gauge on a specific needle size, and often don't knit to the gauge in a particular pattern anyway.
What you would do is look for a pattern for your yarn weight, then use the needle specified for that pattern. That's the gauge you have to match, not the gauge on the label. That's not the 'recommended' gauge or needle size for that yarn anyway, that's the gauge and needles that classify a yarn into a weight category so you can sub similar yarns.
sue- knitting heretic