Go for Linux, that is open source. You can D/L it from various mirrors, depending on which distrobution you choose. I'd Personally do A "google" to find A D/L mirror, that is Geographically Close to you.
__________________ lisp hacker
running: FreeBSD 5.4 - still learning
develop with: SBCL + emacs for lisp, Anjuta IDE +gcc for c, SPE for python..
browse with: opera