You are welcome to build your own kit. A good platform to build upon are the "Do-It-Yourself" kits, that include the cable, clamps, slings and turnbuckle(s) plus a safety stop block. Choose the cable size and the length. All zip lines under 200 ft can utilize the 1/4 cable. Between 200 and 500 a 5/16" size would be used. Anything over 500 feet or in a commercial application we recommend a 3/8" cable. Add a trolley of your choice, seat or harness, brake, and you've got a kit!