You can, of course, use whatever you like, but I think that putting a serif font as an alternative for Helvetica Neue/Helvetica for Linux users is a bit silly.

There's plenty of Helvetica alternatives on Linux.

Believe it or not, but I actually like Libertine and have no particular fixed interest in Helvetica. I could have suggested Liberation Sans, or DejaVu Sans just the same.

I just saw a similar re-layout with Georgia that I liked and was a bit primed for serifs. :)