These guys obviously don't know SHO's.
It's probably a COP (Coil-on-plug). You have 8 of them, they are on every cylinder. It's essentially a coil, but instead of one big coil which handles all your cylinders, there is a smaller version on each cylinder.
There is no way to really tell which cylinder it is until it gets really bad and throws a code. If someone tells you to check for cracks in the rubber boot to see if it's bad, waive them off as this does not matter at all and doesn't make sense.
They can be pricey depending on where you go. Most good ones cost anywhere from around $80-$120 new. You can get eBay ones for as little as $15, but they will crap out on you within a couple months (I would know, I was a sucker and bought them).
Best of luck. And if you are going to do the repairs yourself (not hard), then I would check the plugs to to make sure they are still going strong.
As far as the engine mount question- NO! Your engine is allowed to move and when it misses (or has a slight miss) the engine will move because the angular momentum of your crank is slowed by the cylinder not firing, thus the other cylinder have to pick up some work, and will create the extra jolt of torque.
