If you have a website where I can download for free the font FF Signa or a similar one, I would really appreciate if you can share it with me.

We can't give you a free download, but we can give you a similar one. My suggestion would be Lucida Sans/Lucida Grande.

No, it's illegal.


Not very "similar" but with the same proportions : http://www.dafont.com/bitstream-vera-sans.font?fpp=50&text=ACGKMQRSaegrtu