I'd go with being a miner if I had to choose between the two, I had a grandmaster miner on UO and the high level ores were a great source of income. Plus it was a risky business mining, so the risk added to the price of the ores.
Farming, well, the house is nearby and maybe help if you need it, at the mines, its just you, your packmule and whatever weapons you bring with you.