Make sure they are an exterior grade fastener.
The one on the top would need to be pre-drilled thru the DP, but I like the head better, and is the one I would use.
The one on the bottom is a self tapper, but I don’t like the head as much and would be my second choice.
The key is to silicone all around. Keep the moisture out.
Actually applying silicone all around would just keep moisture in. You can’t keep moisture from getting in so at least let it out. Same reason siding on your house isn’t sealed at the bottom.