How to pick a BPM software?

Hi.
I'm not sure if this is right forum to ask but I will go...
We are going to employ a BPM product in out Java EE application.
The manager assigned to me the task of picking a product.
My main two options are:
JBoss jBPM and BEA AquaLogic BPM
How should I make the comparison? what are the features I have to look for?
As our application server is BEA weblogic, AquaLogic has advantages but I want to make a subjective comparison.
Which product to pick?
Thanks.
[ December 12, 2007: Message edited by: John Todd ]