I'd lightly rubber mallet the lightly greased cups in to start with, then use a DIY press to finish, I've done around 150 headsets with mine including alloy Campy and Hope, no issues
I used one of the ebay ones, seemed ok but doesnt give a even spread of the load on the cup, so had to keep adjusting it, and the plastic washer split apart also. Think I might just try the block of wood next.