So for aluminum channels I use these. I don't use the brackets that come with it because I super glue 4lb pull disc magnets on the back of the channels (4 magnets per 6.6ft channel) so they attach against the metal flashing that is under my shingles on my roofline.

For connection points I use butt connectors to join the wires in a run to waterproof them. Also, I use shrink tubing on top of that. I do NOT silicone seal on the ends of the channels (even though most people would say to do it) because I want water to be able to drain out in case it gets in. The silicone would just keep it trapped inside.

Here is my Amazon Shopping List