matty, is your LS w/4EAT or 5MT? The respective coil packs are different from the factory. The 4EAT is a Hitachi and the 5MT is a Diamond. The Diamond coil packs are a good upgrade to put on the 4EATs.
It's always a good idea to test the resistance of the primary and secondary coils to see if it is within FSM specs. When I replaced the coil packs on both of my subies I combed through (tested w/multimeter) a lot of coil packs at the junk yard to find a few really nice ones. I agree with you that the clip can be a pita the first time you try to disconnect it but after disconnecting a dozen or so it gets really easy. Flathead screwdriver is the way to go. Junk yards are a good place to learn how to take things apart. If you break it move on to the next one, lol.
Here are two pages from the FSM regarding coil pack specs.