I am a pilot who has a weird work schedule, i only work 4 months a year so i have 8 months off a year and i want to learn how to cnc. I want to build prototype golf equipment. So mostly stainless and carbon steel and itll all be 6in x 6in in size. My question is what would be the best machine to buy with a ~20k budget that'll be easy to learn with but also something i can grow into in case it ever becomes a small business. Thanks in advance