The decision between race or template depends on what you want it to be. If you want to be able to make quick and easy elf-robots, dwarf-robots, etc., then make it a template that can be applied to creatures.
If you want it to be a unique race of its own, make it a race. By making it a race, you could include customization options, or sub-races, or something similar.
From what you've said, it sounds to me that making it a race would be best. Keep in mind that you can include choices for individual characters of a race... like "Does this character have the laser cannons, or does this character have the armored body?"
And once you are done making the race... post it here! People will give you good feedback, and you can use that to refine the race into a balanced race that still is what you envision the robots as being.