It will work but the second gauge is virtually useless for kegerators. By the time it tells you that you are soon going to be out of CO2, it's virtually out of CO2. If you can find a single regulator for cheaper go with it. I didn't listen to my friend who is a plumber and I drop another $20 on something that has literally done me no good whatsoever!
I completely disagree, A high pressure gauge is absolutely necessary!!!
Don't leave the tank and regulator in the fridge and it will be accurate. It is nice to know when you are about to scramble around to get you tank filled or exchanged. If you don't have a HPG I would recommend having a great backup plan for serving your beer. Remember the co2 will always run out at the worst time possible, when you have friends over.