BC Racing coilovers and supporting mods.
 

I bought the BC Racing coilover set for my 2018 Camaro SS. The guy recommended I also buy the GodSpeed camber kit arms and the toe arms. I made the purchase without researching and later found that Godspeed is a shite brand. I started to look at BMR parts but no other company calls it a camber kit.

My question is, do I need to buy anything else to get the alignment right after lowering the car? It’ll only be like an inch or two. And if I do need other parts, is it upper rear control arms? Is it lower rear control arms? Is the camber arm something seperate? Do I need the toe arms? My only suspension experience is on a 1983 Mustang with a 4 link that had tubular double adjustable control arms.

Is it Trailing Arms that I need?

spl parts over godspeed for sure they are cheap china

If you're only dropping the car an inch you should still be able to get it aligned with everything else stock(unless you're going for that stance with crazy negative camber). Vorshlag makes quality camber plates if you need them, bmr makes great stuff too, SPL is recognized as the best but it's big money. It all gets expensive quick if you can't get it aligned with stock equipment. I'd certainly give it a try before spending that cash, especially if you're not a track rat.