The lack of replies in 3 weeks is an indication that there is no easy useful answer.
I think that any ETL tool can be used to load data into Infobright, since that only requires producing a flat file.
I expect that any ETL tool worthy of being considered an “ETL tool”, can extract data “from SQL Server/DB2/Oracle (in scheduled manner)”.
That leaves unspecified considerations as the differentiators among the tools.