AJ,
I've created a few benchmarks that are available in my github at
https://github.com/tmcallaghan. You can modify them to work on other databases, but it won't be a straightforward effort.
STSSoft created a database benchmark that runs against a lot of databases and is available at
https://github.com/STSSoft/DatabaseBenchmark. The downside, IMHO, is that the benchmark workload itself is still pretty uninteresting.
Please report back anything you find/create, I'm always looking for new benchmarks or happy to contribute to others.
-Tim