LSD is very important imo, mine is only CT9 but it grips a silly amount, I've not really pushed my car on the road that muc but I could properly feel it working on track, one of the best mods you can do I reckon. Any under brace will be decent enough, but just make sure it clears your exhaust and your roads are not bad enough for it to catch Meisters ftw also, the ride is amazing but they handle crazy too