negation - There is[n't] nowhere I'd rather be than here with you

A. There isn't nowhere I'd rather be than here with you.

B. There is nowhere I'd rather be than here with you.

Elsewhere I have read that two negatives in English destroy one another, although they are not always equivalent to an affirmative.

I'm not sure precisely what this means. So my questions are:

1. What is the difference between A and B?


2. Is A "standard" or acceptable English?