I don't have previous experiences with STEAM before, perhaps better read Steam's rules
in their website.
IMHO If it is just a matter of a couple of weeks, I would first full install that SSD, and then buy and install the Sim.
You can find DVD Collectors Edition in Spain at "L'Aeroteca" (Barcelona) and in "Game" shops I think. Check their websites, but it is quite more expensive than the Steam version.
Bienvenido al Cliffs of Dover, Aidor. Puedes encontrar más informacion sobre él en español
en nuestro foro.
¡Saludos y buena caza!