As someone who has also written database applications in Visual Foxpro, I have never regretted choosing Lazarus. I still use Delphi from time to time if the need arises but I prefer Lazarus for its cross-platform abilities. I however did not have to migrate my old VFP applications to Lazarus so our situations are not exactly alike.
For database application development, I currently use Lazarus + Firebird/SQLite + Zeos. An open source cross-platform combo with favourable licensing.
I don't know about the complexity of your reports so you'll have to try LazReports for yourself to see if it is suitable for your needs. My current reporting needs are not complex so LazReports & FortesReport are suitable for the time being.
However in the long run for very complex reporting needs, I am thinking about using the open source Java reporting tool - iReports
http://jasperforge.org/projects/ireport. It is very powerful & has lots of features including generation of charts. It can connect to various data sources but I'm presently prefer its ability to use XML files as a data source. The idea is my application/database generates the XML files while iReport takes care of the reporting end. This way, I can keep configuration to the barest minimum. iReport also exists as a portable application so with this kind of solution, I can have the entire application on an external HDD or on a CD-ROM which is ideal for demos.
Like I said, this is just an idea I have but I believe I can make it work. I don't know of any open source cross-platform solution that gives you everything from soup to nuts but if you are willing to mix & match, you'll find something you can work with.
Happy exploration!