the only difference is that on non-windows platforms google strips font hinting. That's just a (very minor) performance optimization done to reduce file sizes. Just download the windows version of the fonts (in all of the formats - woff, woff2, eof, etc).. the minor difference in size isnt worth the effort.

You can also just download the ttf files, and run them through a web font generator w/ proper support for hinting, etc... and then you'll have all of the formats you need.