Don't let anyone talk you out of fat slicks. Sure, you can run 35mm tires on your bike. But the 42-50mm tires you were looking at will also be a good choice and be super comfortable. Remember guys, this is for a hardtail 29er MTB. It's not going to be fast no matter what. Skinny tires would be a silly choice in my opinion. I don't often like riding a MTB on the road but when I do I like to have a wide slick tire to take advantage of the offroad/jumping capabilities of the bike.