The most common type of clams that are used for making clam strips are the big surf clams which look like giant steamer clams.
You can also use other types of clams to make clam strips if you want too and can't get any other types of clams in your area however the big surf clams are what makes the best clam strips.
Other clams are used to make fried who belly clams and other types of fried or cooked clams such as the topnecks or littlenecks, cherrystones, or quahogs, depending on their size.
I love all types of clams but always just use the big surf clams to make clam strips at home.