Hello,
Thank you all for your advice. It has been helpful to read you.
I think we will be looking into open source data integration as it seems to be the most flexible option in regards to our business.

A question: what are the assistance and training capabilities open source software gives to their users? We are testing and feel that one day, we might need a better insight of the software.

Thank you for your help.

Open source is interesting as support and training can be given when using an open source solution.

When using open source software -such as Infobright , Talend ...-, you can get support and training. You can also get some free community support from community forums.