Look forward to your future posts, just added you to follow list.
I used a local fence company for installing steel posts when I had put up video surveillance cameras on our property. It came out around $180 per for 12 ft above ground sunk in cement I believe 4 ft.. For connections I like liquid electrical tape for encased(not directly exposed to the outside) connections, for exposed I use sprinkler system silicone sealed connectors from Home Depot or Lowes.
Gridseed orb is a 2-3 year old cute round desktop scrypt/bitcoin miner. Scrypt mining with them generates very little heat and power draw.