Sturdy shovels and a fire beetle. the sturdy shovels (rewards from BODs) had 150-200 uses, as opposed to regular ones at 50, so that maximizes the number you can carry. Use the beetle to smelt, and you don't have to constantly recall out to smelt or unload. I can strip mine for quite some time in this way, especially if you're not worried about color.
Shovels weigh less than pickaxes, so I always use my pickaxes first, and get them out of the way.
I'm carrying assorted stuff, and over 600 ingots, and only takes about 180 stone. It takes longer with a giant beetle, because you have to recall out at 1600 stone, smelt, then come back.with the Fire beetle, you just smelt and keep going, since ingots weigh MUCH less than ore. human characters also have a chance to dig up more ore, so if you're going for sheer quantity, I'd go with a human miner, for that and carrying capacity so you can stay out longer.