Are you guys actually generating PDFs from user input? If so, I'd be really interested in finding out how you do it if you don't mind sharing. I've found a number of apps that allow you to generate PDFs server side but often the installation is near impossible (dependency issues), e rendering is not good enough, or the API makes using it with a web app clunky. I did find a solution (don't recall the name) that actually used Webkit to render web pages and then turned them into PDFs but I was never able to get it to work in an app. It only seemed to work some of the time and only through ssh. But if you can't say, then I can respect that.
[1] http://rstudio.org