Need guidance producing PDF of Invoice Data

Hello.

I am wanting to replace an OLD client-side PowerBuilder app that allows users to query a database by criteria such as invoice number, customer, packing slip, ship date, etc.  The end product is a printable image that mimics our original invoice.  

I want to replace this PITA with a web app that will be more robust and produce a PDF version of the invoice.  I have an apache web server (Apache/1.3.6).  I have limited XML experience.  I will most likely design the application using Perl since that is where my greatest strength lies.  The data resides in an Oracle database.

There seem to be SO many solutions for this problem, but I am feeling highly overwhelmed.  I would just like to figure out what is necessary to get data from Oracle and displayed as a pdf.  I don't believe this task should be too complicated.  

Am I mistaken?

A sample portion of the invoice can be viewed at fierke.net/invoice_sample.jpg.

Thank you in advance for any and all contributions,

John Fierke
Dallas, TX