IBM Lotus Notes is not open source but has reasonable costs and many architectures to choose from. I recommend it for the Workflow stuff and it has been the leader in its field for more than 10 years. It is by far the best workflow and collaboration software on the market. It is entirely programmable / customizable and is the only thing I would use for the problems you described.
For the J2EE stuff I would use JBoss for all of the reasons JBoss rocks.
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IBM Lotus Notes is not open source but has reasonable costs and many architectures to choose from. I recommend it for the Workflow stuff and it has been the leader in its field for more than 10 years. It is by far the best workflow and collaboration software on the market. It is entirely programmable / customizable and is the only thing I would use for the problems you described. For the J2EE stuff I would use JBoss for all of the reasons JBoss rocks.