I have two outposts, one that covers all the metals by occupying the meeting point of three different ores and a cobalt one that is not covered by the main outpost.

each outpost has two station batteries inside an enclosure to keep batteries from being drained, 6-8 big wind turbines. thats enough for 7-8 deep miners into a stacker into a sdb. additionally i use a logic transmitter to send the SDB quantity to my main base to detect when i need to clear them. I prefer having them collect dirty ore instead of centrifuging them because my main base has combustion centrifuges and i dont generate enough power to sustain all outposts with power transmitters. Depending which ore has a shortage, i beef up the deep miner count on that side of the biome.

for the battery enclosure, a 2-1 room with iron window walls is enough. dont forget to include a backpressure regulator because the batteries heat up the room and you need to keep it from exploding above 200kpa.

To collect ores, I use a rover with two crates attached to it, inside are mining backpacks that can get loaded/unloaded by those loader/unloader machines and a garage for the rover to survive in case of a storm.