I concur completely with the call on MSD'*. They are absolutely the best, even over stock. Look at NHRA, NASCAR, etc. All MSD ignition components. Tried, tested, and cheaper.
Yes, heat can affect a coil that reads fine cold....the only REAL way to test them is with a crank-style megohmeter. Most people don't know what that even is any more.
And yes, the #1 will read the lowest. Longer wires should read slightly higher. I seriously doubt you have a bad wire, but the only way to find out what the real problem is........pull your plugs and inspect them. Keep them in order. Reading your plugs can tell you alot. If one or two are fouled.......well, just do it, we'll help you figure it out from there.
Actually plugs are cheap. Just buy new plugs like I did, and read the old ones.