My DS4 and DD1.5 will both take either brand. Matchbox and Hot Wheels are equally durable and cost roughly the same -- sometimes I've found one or the other 2/$1 around the holidays.
How old is your son? My DS4 loves playing Hot Wheels Stunt Track Driver I and Hot Wheels Stunt Track Driver II on the computer. They are race car games where you are racing on a track and the car & track are scaled to the same scale as a Hot Wheels car -- your car can get hit by a cat swishing it's tail or eaten by a frog, etc. Also, the game let's you earn new tracks and new cars as you do well on past tracks. DH and DS4 usually play it together and have gotten lots of entertainment out of the reasonably priced games (~$10).