According to your problem description, EZP 3 is ready for the task, storing and searching customized content (user defined content classes ) is at the EZP 3 heart
Your main problem will be importing your data to EZP 3 DB format, you will need to code in php ( import script ) to do that
If you are a programmer you can study EZP 3 import scripts code, to figure out how to do it, you will find it at the contribution section in this site
Nevertheless, EZP 3 DB is complex so you may have a hard time to do it, if you don't know the inners of EZP 3
