Plugs and wires are definitely a cheap(er) fix to the problem, and likely the first source since no other code is being thrown.

As you've probably figured out, once one cylinder fails, the other ones usually fall like dominoes.

Try plugs first... unless you've had the wires on/off multiple times, I doubt they're bad. One thing about it -- if you do nee to change wires, those are super easy. The plugs are the PITA...