Just save. There is no difference in files between platforms.
There are some Windows-centric font formats that aren't portable, by any OpenType or TrueType font will be portable between platforms.
Unless the text is specifically intended for input by the individual customers Convert to Shape would be an option to avoid font issues.
The PSD format does not embed/include font files. I'm trusting that you are not separately including those font files when you distribute your PSD files. Redistributing fonts files is typically against your license to use them (ie: illegal).