The camber/to kit for the rear is if you want your suspension lower than stock height, typically it consists of adjustable camber arms, aftermarket adjustable toe bolts to replace the OEM ones on the spring bucket perch (these require a Dremel tool to enlarge the factory hole), as well as adjustable radius rods (usually incorrectly called "traction arms".

Front suspension adjustment is typically made with an adjustable front upper control arm (FUCA), the rest of the components usually don't NEED to be replaced unless something is worn out and has play in it.

There are essentially 3 "triangles" that make up the rear suspension and raising or lowering the ride height makes 2 of those triangles change shape, the only one that never changes shape is the radius rod triangle.

Any adjustment to the rear (or front...) suspension height will require an alignment.

Hopefully that helps get you squared away. Look up a YouTube video about (G35 adjustable front upper control arm installation) (G35 adjustable rear camber arm installation), and (G35 rest toe bolt installation). Those will give you an idea what to expect for the instlls.

Some coilovers replace the rear lower spring perch and will also include an adjustable arm to replace the perch. Other cheaper kits will use the existing spring perch so look up both styles.