Consider hosting Acrobat Reader ActiveX control directly, side-by-side with Awesomium. It's quite snappy, here's how it can be done:
http://www.codeproject.com/Articles/380019/Using-Adobe-Reader-in-a-WPF-app/ http://hugeonion.com/2009/04/06/displaying-a-pdf-file-within-a-wpf-application/
The Reader Control API is described here: http://partners.adobe.com/public/developer/en/acrobat/sdk/pdf/iac/IACReference.pdf