Hi Tom - I would push BI Publisher for your customer if they're on any version after 9.0.
I've worked with every one of the forms software out there on various customers. Most of the ones you listed (Optio, Create!Print, FormDirect) - I believe their assets were picked up by companies like Bottomline Technologies when they suffered major devaluation on the stock exchange in the early 2000's ! The reason was that most of them were more "image" based - ie, they didn't adapt their technologies to XML - and instead performed image recognition on the PDF's. Optio specifically was horribly slow when they re-wrote the product in Java to be platform independent, and caused major performance issues at many companies I worked with, let alone the complex "specific" tool that Optio provided was difficult to learn and caused a lot of issues if a PDF output changed slightly from JDE (ie, Tools Release changes could theoretically break Optio forms !)
BI Publisher Embedded Edition is freely available to use for any customer above EnterpriseOne 9.0. It utilizes XML Output, which ensures that tags are correctly adhered to and output should certainly not change between tools releases or even minor ERW changes. The "tool" for modifying the forms is Microsoft Office (RTE files) - as well as the standard JDE Toolset (OMW and a Fat Client) - hence customers find it relatively easy to create their own forms after a little training (there are even videos available on the Oracle knowledge garden). I believe that BI Publisher answers MOST form requirements - if you want to transform output into something with graphics and/or barcodes, then BI Publisher works.
However, if you want a little more, then Bottomline provides functionality that is more "Document Management" rather than just plain "Form/Output transformation". Bottomline acquired most of the other form-output companies assets, and their product now is quite strong, and provides more functionality than BI publisher embedded on its own HOWEVER it is expensive - and to be honest, if you cobble together a few other products out there (such as Autoprint from Everest) to BI Publisher Embedded, you can answer most of your requirements.
Lastly, the "Cadillac" of course is a mixture of BI Publisher Embedded, BI Publisher Enterprise (driven by OneView) and Oracle Document Management (now called Oracle Webcenter Content). If you are a larger, Enterprise customer - then that cocktail will answer every single requirement you can imagine - but it is not cheap ! Add OBIEE for Business Intelligence and you're starting to get preferential treatment from Oracle themselves (!)
So I would definitely start with BI Publisher. If your customer has more requirements that can't be directly addressed with BIP such as fax and email, then look into AutoPrint and eFax accounts....