copper vs pvc compressor lines?

From your compressor you should have metal pipe( I prefer copper) sloped upwards to a filter and primary regulator. 20 feet is optimum, you can zig zag it if necessary.
This allows moisture from the compressed air to condense and run back to the compressor tank where it can be drained. I have used this setup in several auto paint shops and have never had to install a receiver drier to eliminate moisture at my sprayguns