You do need the longer shocks on the rear, and the crown vic shocks are a good choice, but you will need to pound the metal bushing out of the stock shock lower mount, to use in the crown vic shock. You'll notice the opening for the bolt on the crown vic shock is too large without the bushing. You can also use 1995 ford mustang shocks, which bolt right up.
As for the struts, the stock struts are fine with this kit, but as Jeff mentioned you will need to add his strut spacer to account for the spring spacers. Jeff's instructions call for the strut plate studs to be drilled out, I found a couple hard smacks with a hammer and the pop right out, much easier and faster, just support the plate well so it doesn't get warped.