Did you try the current console and look at the existing features?
You can create the forms for human tasks using Freemarker(http://freemarker.sourceforge.net/) templates. Freemarker is a template engine to generate HTML pages.
The console (based on https://github.com/heiko-braun/bpm-console/raw/master/doc/Reference.pdf) provides the framework using GWT and REST. This framework gives you the integration with jBPM runtime engine. Having said that, you would need to extend it based on your needs, such providing access to your data model and integarting with any of your custom workitem enhancements.