If you are mining around bedrock, then its not easy to get solar power there. You would have to make a hole to the overworld and then solar panel and cables.
I would go with the teleporter systen. If you have dark matter, then it wont be a problem. The thing might be the time it takes to empty the chest. If you use the hammer, then it would get filled fast, and you would need alot of energy to pump it out.
Ruby, emerald and sapphire are both as fast in mining speed as diamond, but only have the durabillity of iron. My list would probaly go like this:
Wood, cobble, iron, gem, diamond, drill, DM and then RM.