Ask HN: Recruiting and paying cross-border remote staff

Unfortunately, we have a very limited local talent pool, and we are looking at recruiting remote staff. We have extensive experience working with freelancers, so there isn't so much of an issue with the management side of things. What I am having a hard time finding out about is what are some effective ways to hire permanent staff for remote work, and how to pay them, dealing with Social Security payments, PAYE etc. when you work cross-border with someone. does anybody at HN have any experience with hiring and paying for example US staff from an EU location?