It is very simple to test a coil pack. Just pull it off the plug and listen to see if there is any change in the sound or rpm of the engine. If it doesn't change, the coil is bad. You can also buy a simple cheap tool and test it:
Actually, I think your problem is more likely a bad injector or fuel filter. I think the filter is in the tank? There are several simple test to check injectors:
Also the test can be performed with an engine stethoscope, a very cheap and useful tool. Finally, I'm not a fan of replacing parts en masse. I like to exactly identify the problem and replace only that part, because parts especially on my vehicles are very expensive.