I work as a remote employee for a us based startup out of India. I raise and invoice every month corresponding to the salary account.<p>For all legal purposes, I'm a consultant to the company.
every time I've looked at remote (out of country) work, it was always as a contractor/consultant. Never as a true employee. That way the company pays an invoice, the contractor handles all their own taxes.<p>Treating your "foreign" remote workforce as employees I imagine will land you in some tricky international waters much better suited for your accountant, tax attorney, and your general business lawyer.
All of my remote contractors invoice me weekly. We just use a shared google spreadsheet that track times on one tab and sums it on another by week.<p>I actually handle payments via xoom.com -- it is now owned by paypal. It takes a little work to setup a new payee, but once you have paid a person once, you can pay them again very easily.
If they are US citizens then whichever way you would pay the non-remote probably. If they aren't, then they will tell you which is best for their situation/country according to what's available there and the lowest fees.