Can I use Arduino instead of PCB?

No, this is not a good fit for Arduino.

Arduino boards are not intended for use in industrial environments and the interconnections are not rugged. The software and documentation is largely produced by amateurs, and is not particularly reliable.

It would be much, much faster and easier to have a few hundred boards manufactured and populated, than to assemble the same quantity by hand (using off the shelf parts), and the result would be much more reliable.