Replacing an old HDD with something new.

I need help, badly it seems.

I just read the verge's post about Windows 8 versions, but it didn't answer my question.

I want to buy a new HDD, install a fresh OS on it as if it was new. How can I do this? Which Windows 8 version will do this for me? And what are great options for a new HDD, whether it be a SSD or a standard HDD.

Thanks in advance!