In practice, the difference is functionally nothing. Where I work, PAs and NPs do the exact same job and our MDs rarely remember and certainly don't care about what we are. Technically NPs have their own licenses and PAs don't but it isn't a meaningful difference in practice.
One major difference is that PAs are generalists in the same sense that MDs are - they're supposed to be competent at everything. This gives PAs a lot of flexibility. They can bounce from peds to surgery to ED quite easily. Becoming a PA is a great choice for someone who wants that sort of flexibility or isn't sure what they want to do.
Nurse practitioners are not trained as generalists. We're all trained for specific populations like family medicine, pediatrics or adult/geriatrics. It can even get really specific - I'm an Adult Acute Care NP which basically means I'm trained as a Hospitalist/Intensivist. In my case, I can prescribe and treat acutely ill adults but I'm functionally a nurse if I run into a sick kid, primary care or women's health issue. It's a key difference between the professions that most folks don't really get.
NP is a great choice if you're certain about what you want to do and what population you want to work with.
Either choice is good though. I can't speak for CRNAs, but the NPs and PAs I know are all happy about the decision they made.