Here are some (All Commercial) I came across when looking for something similar:
VisPDF Library - This is worth checking out and you get source.
PDFDoc Scout library - This is an ActiveX control and you don't get source but has some good features (good HTML to PDF conversion for example).
PDF Creator Pilot - Worth checking out too.
I found that the freely available ones LibHaru, PoDoFo weren't up to scratch for my requirements unfortunately.
