The solution is to use gmcs: an IDE that allows you deal with references as part of the project configuration, rather than making you fuck around with the command line just to build a trivial proof-of-concept app.
SharpDevelop is still not working even after adding those two references and telling it I want Mono 2.0 not Mono 1.1
So I'm going to use it to throw together the interface, and then stick to jEdit for writing the code with the simple batch file I created for compiling. :P