Hi: this one is a miser solution, but works: I've used an IDE wire (cut it and use each extreme to connect to each file of pins) to put one L298 and one 7805 into a CPU heat sink+fan cooler. It hasn't heatsink grease or mica (I think it's bad).
Thanks for this great post (please, post the schemas ;)!!). Btw. someone could explain how connect the L297 to a darlington for unipolars (or two L297 plus one ULN28003)??
Regards:
Nach.