Unless they specifically want threaded pipe I would consider looking at Speedrail. There are more fitting options to attach the legs to the table top, you have a better ability to add intermediary supports, you can avoid all threaded connections if you prefer, and you are not limited to stock lengths to build your table as you cut the tubing to length and secure all fittings with hex screws. You also get the benefit of no future surface corrosion as the components are made of thick walled aluminum.
If you consider this route, you should know that all dimensions are I.D. It is a common mistake for people to assume it is O.D. and are quite surprised when the materials arrive being larger than they expected. You would need to paint it black as you have already indicated you are willing to do.
Good luck with the project!