Searching for 1.5 upgrade

I will say up front that in all honesty I am probably too ignorant to even be attempting this. However, I never upgraded from 1.2 to 1.5. Everything I have read instructs me to upgrade to 1.5 prior to upgrading to 2.0 but all the download links take me to 2.0. Where can I find a 1.5 d/l?

We are ready to chuck out our old templates and what not, the only thing we care about keeping is the archives. Is there a way to clean install 2.0 to my current blog addy but still access the old archives?