$20k machine will not be appropriate for profitable
sign production. To compete you will need to make a lot of
signs, buy and warehouse truckloads of materials, have a vacuum and air cleaning system (the dust from wood and foam is toxic), have an acrylic polyurethane painting system and ventilated spray booth (check you codes), shipping department and contracts with several forwarding companies, lots of climate controlled space, and a ton of employees, managers, administrative and sales help and everything else needed to run a production business.
I would recommend outsourcing production until you are doing at least $.5M/year exclusively in dimensional
signs (unless this is a hobby and you just enjoy doing this).