Correction....
Gold is the best conductor of any of the stated materials, High end car audio connectors use gold or gold plated over nickel, since the amp draw is high.
It also prevents signal interferance........
Silver would be the next best thing.
Copper is not far behind Silver and is far cheaper...
Aluminum is not a good conductor, I know I use to have an aluminum Jetski trailer and I had to run seperate ground wiring so the tail lights would not blink with the turn signals... The trailer itself was one big ground loop...
Why do you think they no longer use aluminum wiring in houses????
It corrodes and the expansion and contraction is different from other materials used on the circuit, one thing it does well is disipate heat well.
Sukh stick with the muchmore bars or try the niftech they are lite weight & cheaper....
Grant