I don't think a trip to the Apple store is the best idea. I think you should just get one for your father and see how it goes. You can always return it within the right time (30 days?) for a full refund.
My cousin got the original iPad for her father a couple of years ago who was turning 70. He didn't think he would like it when he first opened the box but now he and his iPad are inseparable. He is on it all day every day.