The custom saber shop already has his own design for a "drop-in" heat sink/led module that fits the MHS, so I doubt he'd be interested. Most other custom built lightsabers usually have either a 3/4", 7/8" or 1" inside diameter for the blade to fit inside, so any other kind of led module would likely need to fit within those dimensions. As far as cooling goes, it really depends on what kind of heat the led's generate. The thing to keep in mind with the design is that cooling fins and such on the heatsink are nearly useless inside a hilt, since there is no airflow within them, unless you add a small fan, which would not only take up valuable internal space, but also draw extra current from the battery pack, shortening the run time. Lightsaber heatsinks work best with as much surface contact as possible between the led module and the outer parts of the hilt as possible, so the heat can be drawn out from the module, and dissipated on the outside of the hilt.