jBPM5 contains the best of jBPM 3/4 and Drools Flow, so definitely go for jBPM5 in this case. Note that the concept of a PVM where you can implement your own node types still exists in jBPM5 (as that is simply how we implement each node type that are supported by default as well). And it probably contains out-of-the-box implementations for quite a few of the nodes you mentioned as well.
Kris