Presently I've got a custom tool which creates vanilla-SQL (only using standard SQL), from your Data-models that creates database schemas and initial data for the new databases, and do version patches, etc... This part is good at this time.
However running these SQL scripts against all of the different databases (different suppliers) is really a discomfort, and so i authored up a fast little Php script some time back that will it for me personally, but I'm wondering if there's much better fix for your problem?
I personally use SQL Developer, it is awesome.
It runs in almost any plataform (is really a Java application), you can connect with any database vendor and it is free.