Yes you should definitely do your own POC and set aside a good time period to do your own investigations, and try out the products - eg kick the tires.
Many of the open source products is free to use. And if you want FuseSource offers subscriptions.
http://fusesource.com/enterprise-support/support-offerings/
In terms of BPEL, I would not recommend that. Its not really catching on anymore, and is becoming legacy/dead.
Instead you may want to look at BPM. We had a discussion on this recently at the Apache Camel user forum
http://camel.465427.n5.nabble.com/Camel-EAI-patterns-vs-BPEL-processes-tp5713573.html
Kai refers to BPM and he did a recent talk at CamelOne about using Camel and Activiti together. The video of his talk will be published soon on the CamelOne website, when the production company have processed all the videos.
http://fusesource.com/apache-camel-conference-2012/
And there is a book Activiti in Action which is soon to be published
http://manning.com/rademakers2/
At least I would suggest to kick the tires of Activiti combined with Apache Camel.
And then maybe check out the Fuse ESB Enterprise, which is a great container for running your applications
http://fusesource.com/products/fuse-esb-enterprise/