For one piece, I think it is better to look somebody in Lahore.
On OLX, search for Fiber Laser or Laser Marking. You will get plenty of ads from people who are selling these machines. I hope they can tell you some place where they have sold their machines and you may get one piece done from that place.
In Sialkot these machines are used for marking on surgical instruments. There must be some setup in Lahore as well.
The Islamabad guy will not deal in one piece, I know.