Third-party library for converting images to pdf and eps on the fly?

I have a future .NET project that needs to convert an image (bitmap) to .pdf and .eps format. We would rather use a third-party library tool to do this rather than waste time inventing the wheel. Here is the basic requirement:

• Preferably a clean .NET library (we can put this converter code in a Silverlight application that will not have access to unmanaged code).
• Ability to read input and output output on the fly (in memory).

Any recommendation?

Thank.