Upgrade Path Advise

I am looking at developing my upgrade path to move from GW 8.0.2 to GW2012 SP1 and it appears that I have a few hurdles to jump over in order to get to perform this upgrade because my server's current operating system is SLES10 SP3, OES2 SP3. I was advised to just upgrade to SLES/OES11 with the latest service packs so I'm trying to develop the upgrade path and determine the amount of downtime that I will need to plan on, as well as possible recovery points that I should create in case the process goes sour in the mean time. Please feel free to comment or advise on the following plan for any gotchas that you may have experienced. FYI- I have 2 GroupWise servers in VMWare ESXi.

1. Take snapshots of both servers
2. Upgrade from SLES 10 SP3 to SP4. After reboot verify that GW still works, take new Snapshot.
3. Upgrade from SLES 10 SP4 to SLES 11 SP2/OES11 SP1 using boot media (ISO Images). I expect GroupWise 8.0.2 to break after the upgrade, but once everything has completed take a new snapshot.
4. Upgrade GroupWise to 2012 SP1 on both servers (we have Danita's guide). This is a point of no return, once the Schema has been updated for GW2012 if I revert back to a previous snapshot I'll likely have issues. Verify that GW is working correctly and keep fingers crossed that the update is complete.

Does this seem a simplified version of what I should expect to do or is there anything else that I will need to take into account? Thank you!