I highly, highly, highly recommend that you do not erase that Vista Recovery partition.
It's not very large, and will save you a mountain of headaches using the multiple recovery DVDs if you ever have an issue.
Also, you should consult with the distros in their own fora on their installation of GRUB.
I've found that once you get past 2 O/S, some don't include all Linux installs in their GRUB, and you have to manually add them.
I would install Puppy first, then (x)Ubuntu. PCLinuxOS is the only distro I found that adds every install to GRUB, including multiple linux installs. However, Mint may do so, and newer (x)Ubuntu, also.