I have OES1 right now and I don't want to do a OES2 inplace upgrade.
So can I have OES2 as a replication server under OES1 and then switch OES2 to master then drop OES1?

The problem is my OES1 server is better then the one I plan to use for OES2 (if its possible to do it this way).

Or is the inplace upgrade good enough that it whole blow my OES1 install half way through upgrade?