Over the years I have seen lighting projects put out for bid using a specification written by and/or favoring one specific manufacturer or supplier locking in the product to the project with excessive costs to the customer. WAIT! Where public money will be spent for a specific product type (lighting, electronic message centers, etc.) go the RFP route as you would in seeking an architect to design your next building.
How to proceed: Contact major manufacturers or their suppliers inviting them to provide recommendations to meet your needs. You have the option to make general requirements to be met, but keep these generic not favoring a specific manufacturer. Such requirements may be based on existing conditions, location, schedules, controls, and timing. The next step is to evaluate the quality and the costs with equal importance to avoid getting the least expensive low quality products and services to meet your needs.
Once you have narrowed down the product and services, the rules you have to live by may require this be put out to bid. No worries. List the specifics and leave open for equals. In the final decision it is strategic to make sure equals are no less than equal. In the end, you will have a selection that will make the best use of your resources, and allow you to sleep at night.