What is the right wiring harness for the Honda Civic LX sedan 2006?

I have been driving all over my town, and this seems to be the hardest thing to find, I went to the safe haven Walmart and looked for my car, and the model stops at 2005 and the one that is preferred for my car is a scosche ha10B but I looked it up, and it's only meant for a 4-speaker system, and I have a 6-speaker system. Should I just try the ha028 for my Honda, I need help please, this is going to be the most stressful project thus far.

Go to Best Buy or similar store.