You should be familiar with the IDE cable for your computer. You can buy two 5-meter, 16-pin IDE cables and connect them yourself to a copper connector or your own interface. If you have two 16-pin cables, you can separate them into four individual wires. If you have one 16-pin cable, you can separate it into eight individual wires. You can also use eight 4-pin cables, which would give you 32 ground wires. This setup should be sufficient for most scenarios. It is a cost-effective option for large quantities, and it also has insulation.