the version that comes with oracle 9.2.0.1 and patchset 3 (9.2.0.4)
Or we could (if it is to be standalone) use 10G for it - but the other databases are on 9i and cannot be upgraded yet, is it ok to mix the two (i.e. monitor 9i databases on different servers from a 10g enterprise manager console placed standalone on its own server)?

Is there a user guide/documentation for this product somwehere ?