you made a heck of a choice. The 392 is a beast!!! as for warranty, its basically the same for any other car that you want to mod. For tuning I'm not sure they cracked the 2018 pcm's yet so for now that might not even be an option. Look into the Tazer by ZAutomotive. Its not a tuner but it unlocks the SRT features.
The only thing I do know from some reading is that if you are going to do any kind of boost above 5 to 6 psi you need to go forged internals