10.5.8 and cannot find the download to upgrade to 10.6.8....

I can't download the new itunes and update java on my computer because I am currently running at 10.5.8. I tried to find a download to upgrade my server but it appears that the new upgrades are not compatable with 10.5.8 and then to update on the Apple website I need at least 10.6.1. See my problem? I'm stuck. please help!