Question about best oil for timing chain rattle at startup on 06 Colorado 2.8L (Atlas engine)

I can't see how any oil is going to stop chain noise. I guess if you're in that period where all the oil may or may not have drained out of the tensioner by the time you crank it again, a thicker oil may drain out slower.

You almost certainly have a leaky tensioner. Perhaps the "timing kit" didn't come with new tensioners, or it's got a bad tensioner out of the box.

I wonder if the OP can tell us if this is a OEM kit or something else picked up as a bargain?
Are you sure it’s not lifter or hydraulic lash adjuster noise? Just playing devils advocate, they can sound very similar to timing chain noise at startup.