I personally haven't seen many ERP packages in the open-source arena that do much more than simple stuff - and as such aren't that useful. But, I've heard that these guys make a decent product - http://inoideas.org/ - it might be worth checking out.
The biggest open source ERP in terms features and functionalities is ino ERP, and it's PHP based.
inoERP is quite complex and you might get lost if you have not worked in big scale ERPs sch as Oracle/SAP. (it's far more complex than ban, Microsoft)
If you are looking for something simple then can try webERP. webERP has a very old architecture (PHP 4 kind)
What you are looking for is called configure to order business process. Configure To Order (CTO) can be achieved in different ways 1. Creating a new configuration from a model every time a order/lead is created. 2. Using some standard configuration and creating a new one before quote/sales 3. Using a hybrid model.
Most of the ERP systems (Oracle, SAP) have these basics features but if your budget is low then you can look for open source ERPs such as inoerp!
Have you considered setting them up with an ERP system? Here's one that's open source, and based on PHP: http://inoideas.org/
Also, you may want to browse templates in the MySQL documentation, and even MS Access to see if someone else has already created what you're looking to do. Then, once you get the basic database framework set up (not easy to do), then you can learn how to create custom queries, forms, and/or reports to get out the info you need (for thank you cards, etc)