Not to sound discouraging, but a better option would be consolidating all Solarwinds products - LEM, WHD, NPM, NTA and others on a common DB platform.
First choice would be MS SQL (as most SW products already have a MS SQL option)
Other choices - MySQL, PostGRE ..
Oracle is an expensive choice (My View)
I know that Oracle is so expensive.
But we also pay high price for solarwinds.
Solarwinds is a great monitoring solution and other great monitoring solution support oracle.
Performance is so diffrent between oracle and mssqol