General architectural questions regarding Linux distributions

Hello,

Do I correctly understand that front-end and all nodes must use the same Linux distribution?

What distribution is most recommended to use under Opennnebula?

What is the correct way to make platform migration on the fly if I choose one distro and later on decide to test Opennebula with another and keep all current configuration?

PS opensuse is unsuppoted, am I correct?
PPS BTW is there any way to use self-hosted configuration for front-end? a-la oVirt

brg,
Serhiy.