How to install Pages, Numbers and Keynote on Snow Leopard? I just purchased a used 2006 MacBook Pro with OS X 10.6.8.

I went to the Mac App Store and tried to load Pages, Numbers and Keynote, and it said it could not load them unless I had 10.7.  When I try to upgrade to Mountain Lion, it says my computer does not have the requirements. I can't find Lion—not sure if I could even upgrade to that?  

My question I guess: Is there an older version of Pages, Numbers and Keynote that I could get that would work on my machine as-is, without any upgrades?
iWork can still be bought online. Here are search results for iWork on Amazon.