Do these bolt straight into my Sierra, or do I need custom brackets?

These mount at factory rocker points — no brackets or drilling required. Disconnect the OEM harness, unbolt the old lights, and bolt these in. Installation takes under an hour per side.

Are the haloes and projector bulbs already installed, or do I source those separately?

The halo rings and projector optics come factory-assembled in the housing. You're installing the complete unit as-is — no bulb hunting or wiring aftermarket LEDs.

Will the chrome housing stay clear, or does it yellow over time?

Chrome housings are sealed during manufacturing to resist UV and oxidation. Keep the headlight lenses clean during wash days to prevent water spots, and they'll stay sharp. If the chrome finish begins to dull after years of sun exposure, you can refinish or swap the pair — replacements are affordable.