Create a workspace to work with PDF (C#)

Question

I want to create a workspace with certain size (103x82cm for example) like an indesign-like environment where PDF pages can be arranged in a certain way, which is called impositioning:

I've learned about PDF libraries, but to me it seems like they do jobs like merging, importing, saving etc... I couldn't find something to manipulate the PDFs like the way I need to. Anybody knows one?

Thanks in advance.