My suggestion would be to install in this order:
2. Ubuntu or Fedora Core
3. Ubuntu or Fedora Core
Suse will pick up the other installations and setup grub for you (it's quite intelligent about this). Also, which ever Linux distro you install first, let it make the swap partition. The others will just start using it.
I regularly test several distributions at a time, and have my test systems set up with 14 partitions. Suse will correctly detect each other partition, what is installed on it, and what the boot parameters are for that distro. Plus you get a really nice looking boot menu.