Dear Hugo,

You might want to look at Craufurd Goodwin's essay on the the history 
of economic thought in the new Palgrave Dictionary of Economics. This 
is probably the best single source you will find for the purposes you describe.

There is also the 2002 HOPE supplement _The Future of the History of 
Economic Thought_ edited by E. Roy Weintraub. The volume is much more 
heterogeneous  than Goodwin's essay and has many points of view about 
where the discipline is (and is going). It can give more breadth to 
your view of the discipline.

Finally, you might want to look into some of the  methodological 
essays in  _A Companion to the History of Economic Thought_ edited by 
John Davis, Jeff Biddle, and Warren Samuels. These essays can help to 
give you a better view of some of the different frontiers for doing 
research in the field.

Yours,

Brad Bateman