I did the backup lights and side marker lights on my Camaro a while back and just love them.
The backup lights do indeed require resistors to turn completely off and not cause a battery drain.
However the side marker lights work perfectly without resistors.
I have not yet done the brake lights but plan to in the near future.
It should be an easy matter to search for the LED equivalent of the OEM bulb.
RockAuto.com is a great resource for this.
I buy parts through them all the time.
I think that this link is for your car based upon your "garage"-
https://www.rockauto.com/en/catalog/...ght+bulb,13716
It indicates a 7440 bulb, which is the same as the backup light bulbs.
They do have an LED version of it.
Be aware though that you are very likely to need resistors for them no matter what the LED manufacturer may claim.
Love the LED headlights by the way!