iFixit does sell the lightning connector and headphone jack assembly. And this assembly includes the 2 home button contact pins.
This is the part that you should be replacing. You just can't see those pins on the picture because they are on the other "side" of one of the flat cables.
One additional note: you can source the assembly from suppliers other than iFixit for a cheaper price (down to $10), however this is a critical spare part that may fail often if poorly made, also may adversely affect the battery, the logic board, the charger and the lightning cable. Consider this before buying a cheap connector.