I don't have any experience with either of them, so sadly I can't help you with those questions.
Hmm...Good to know! Today, we went out and bought a FURminator, but I think I bought the wrong size, so I'm going to return it soon. We did the FURminator first, before a new food, but should I get the food instead when I go to return this brush?Diet is number one for an an allergenic dog. Have you ever looked into raw feeding?
I have friends that couldn't pet my dog when I first got him, spent his first 5 years eating Acana and he developed allergies to wheat and grains. Immediately switched him to raw, within a couple of weeks, he's hypoallergenic.
I don't think raw is the way to go for our family. I don't particularly like the risks associated with this, and it's expensive, and I have a big family. We also don't have a ton of money, and feeding all those things sounds pricey...A brush isn't going to work, its not the dog that your father is allergic to. It's the proteins fluffed off the skin, proteins from the saliva etc that's affecting him. And most of that stems from dog food.
Raw is great, been feeding for over 12 years now. But you really need to read and research canine nutrition, can't just jump into it. Pays off in spades tho. The dog is a carnivore.