Yes, the lights are the primary. BTW, there are other threads on this one, but so you know if you're considering it...
The standard headlights are NOT configured to be compatible with the HID headlights. You can't just order the HID's @ $600/each from GM - the wiring is completely different. Not impossible to do if you know what you're doing, but not necessarily trivial either. I was considering doing so on my 2LT, as I essentially wanted the RS package without the spoiler. Caved and went with RS anyway.
