Advanced purchase requisition approval in AX 2009?

Has anyone successfully completed a multi-level workflow approval project for purchasing in AX 2009 either with a bolt-on solution or an extension of the native workflow engine?

I’m trying to identify a solution with the following requirements:

· Email approval

· Parallel approval processing

· Budget checking

· Dynamic approver selection with validations for approval dollar limits.

· Purchase order sent via email upon approval to vendor/ purchaser

· Multi-company support

· Multi-currency support