Yes they are common now, don't go slick though, a little tread helps a lot if you are turning and the tire is off the main contact patch.

I'm sure a member will post with brand recommendations (I ride the knobbied tires on everything, Dangerous urban traffic situation? Jump the curb, sidewalk, onto somebodies lawn and to safety!)

Mid priced tires should do-cheap tires are just that.
Try using the search forums control and use key words- You might find member preferences. Mtbreview...product reviews.

Order online if not available.

Hutchinson and Michelin are 2 mid-higher priced companys that are 'advanced rider' purchased.

Put more weight in the bags later after he gets used to the bike.

Peace.Jef