I have selected the majority of parts for the switch mode unit. Now I am stuck on magnetics design and it is proving to be more difficult than I initially thought. The topology I have selected for this unit is a forward-mode buck converter, the selection for which was based upon an app note by ON Semiconductor that I have uploaded to the project files. The main  motvation behind doing so was the simplicity of the buck converter as compared to the other option- the flyback converter. Simplcity here is a relative term.