OP,

Yes purchasing an intake horn would prevent you from having to purchase the entire EGR delete kit.

Since horns start around $300 and go up, I'm not sure there is much savings there.

Regarding the high flow grid heater some people were talking about, remove the stock one, as it creates a lot of back pressure in the intake tract and there are many claims it robs air from cylinders 5 & 6.

The high flow heaters do the same thing as the stocker does, it just does it with out impeding the air you are trying to force in your cylinders...

 

Emissions grid, that dude is funny. , he really knows his Cummins stuff

Here's an explanation from one of my cummins manuals:
Grid Heater

Feature Description

The air intake heater control helps the combustion process while starting in cold temperaturesby controlling the heating elements in the engine's intake air system. The ECM controls theheating elements in two phases, pre-heat and post-heat. The amount of time that the intakeair heater remains on depends on the intake manifold temperature at key On.

Pre-heat

(after key On and before cranking):At key On, the ECM checks the intake manifoldair temperature. Based on this temperature, the ECM lights a "Wait to Start" lamp andenergizes the intake air heaters. After a calibrated period of time, the ECM turns off the intakeair heaters and the "Wait to Start" lamp turns off. Once the lamp is off, the operator can crankthe engine. Pre-heat time increases with colder intake manifold air temperatures.

Post-heat

(after successful engine starting): During cranking, the intake air heater is turned off to allow maximum current for the starter. The post-heat phase starts after a successful enginestart. The ECM cycles the heaters based on the intake manifold air temperature at key On.This cycle can operate for several minutes on very cold days before the heaters are de-energized. The post-heat phase controls white smoke after startup.
It is not an emissions related component.