Hi Joey
Welcome to the forums

I think that if you are going to get a
dtg for your mall store, that is low on maintenance I would not get one that prints on dark garments, but one that only prints lights. The brother gt541 has a very good reputation for printing on light garments only and does not requirer much to print with it, as it does not use a rip program, where as all the others do, so that would be an extra thing to learn for your employees. I think the brother would be a fairly easy machine to learn.
also for some great graphics for
dtg printers you should check out digital art solutions. They have a ton of designs that are super easy to customize with their program smart designer. Its really very simple to use.
Those are the easiest ways I can think to modernize that would be the most effective adding a
dtg with new updated graphics. If you need any other help just ask. Also our
dtg section here is full of information that might help to learn what the differences are of the machines, and what they can do. It does sound like you should steer clear of any machine that prints white ink though, as you really need to know what you are doing to run them, and your employees could get you into trouble with that one haha.