Worth doing before any of the bulb or housing spending above: if the lenses themselves are oxidized, a hazy lens scatters light that should be going down the road, and no bulb fixes that.
Full hands-on writeup of the wet-sanding and coating process on a heavily oxidized set of OEM lenses — masking, the exact grit sequence, the coating timing and the aerosol safety guidance: How I Restored the Oxidized Headlights on My 2007 Avalanche
Discussion thread for methods and results: DIY Headlight Restoration on My 2007 Avalanche — 400 to 3000 Grit + Coating