Ok David, Rattlehead and FAE Cazador, thanks for the info,
In that case, I'm going to buy the DVD rom version. I found here in Barcelona the collector edition (64'99 euros), only 15 euros more than the Steam version. I can't see the advantage of buying the Steam version.
The last question is not solved yet, but is not a major problem:
any problem if I install the game in two diferent drives simultaneously? Well, If I have to uninstall the first installation and then install in the SSD drive, no problem with that.
I'll need to install it in the Steam folder or assosiated to my Steam account?
Thanks once more! Gracias por la bienvenida y saludos... me pasare por el foro español, claro.