Upgrade VMWare 4 to VMWare 5

Hi,

I am in the process of planning an upgrade of my VMWare 4.0 environment (3 node cluster) to VMWare 5.0 (highest supported on my hardware).

Please can someone verify the following strategy:

1. Build new x64 VM and install VCenter 5.0. Patch to most recent CU - Can this VM be part of my existing VM environment (I don't really have a choice)?
2. Migrate configuration from VCenter 4.0 to VCenter to 5.0. No downtime / impact to VMs at this stage.
3. Add / Manage existing 4.0 ESX hosts from new VCenter 5.0 machine. No downtime / impact to VMs at this stage.
4. Take each ESX host at a time, enter maintenance mode, and upgrade from ESX4 to ESX5. If I don't have the capacity to vMotion my VMs first to another host, can I safely power the VMs down and still upgrade the host (in maintenance mode).?
5. Upgrade VM Tools on each VM. No downtime / impact to VMs
6. Upgrade datastore from VMFS-3 to VMFS-5 No downtime / impact to VMs

Can you just verify I am correct with the downtime / impact?

Can you verify that I can do this all from the VMWare 5 ISO?