That looks cool. But I wouldn't get one without a rain fly. Check Amazon for competitive pricing. Warranties on tents are handled directly though the manufacturer anyway.
Your idea is excellent. My daughter bought her own tent when she was 16 and usually used it when she went with us. She's 30 now and still tents with her husband.
All that said, make your son responsible for the majority of the setup. You might have to help him hold up a couple of poles, but for the most part there is no reason you have to set it up for him.