What overall height over the ground would "3-4 feet over the cage" represent? I ask because that sounds uncomfortably low to the ground if it's less than 20 feet or so.
You will also need to consider light distribution - a 16 x 55' area lit by two lights on poles mandates specific patterns depending on pole height/location and desired light distribution. I'm going to guess that since this is a batting cage, the lights would be best located where the batters are standing pointed downrange so they can see the ball coming and any spectators can also observe.
I should disclose that I am hardly a lighting expert, nor do I play one on a youtube channel. Someone else may be able to offer more specific advice and/or ask additional questions to help with this project.