I'm sure nothing that would help you,
but do have some code I had put together awhile ago (from some tutorial on how to parse html) that I changed to renders to postscript. It doesnt handle javascript ... thought maybe one could push that through Node. Its all written in perl. ... if anyone wants to look at the code I could upload it somewhere.
You do realize that HTML & PDF are by definition are fundamentally incompatible technologies. And if you're asking for something like have HTML form get translate into PDF form with fill-in data, that submits the entered data to a server ... it wouldn't work without a custom nonstandard PDF viewer application that would...