what machine do i need to cut metal?
Plasma cutters are designed to cut thick metal (1/8+ more or less). They are not really ideal for cutting thin metal, though you can do it. The thinner you go, the faster you need to cut to get qood quality, but to get a CNC setup that is precise enough to cut accurately at high enough speeds to cut thin metal you need to spend a lot. Even at the best, you will not get the same precision out of a plasma compared to a laser. You can spend ~$50k for a HD plasma cutter (not the CNC machine, just the cutter) that gets near laser quality, but it is still not as good. Plasma cutters are considerably more expensive to operate.