Okay well the S2K projector setup, albeit an expensive one, is probably the highest quality retro one can do on a Hoe ... let's put it this way, if I had a Hoe that's what I'd put on mine.
So you'll need:
S2000 projectors
Clear lenses if you want a sharp cutoff (no need for lens swap if you prefer the more hazy oem cutoff)
Shrouds (probably Gatling cause they match the tahoe design perfectly)
Ballasts (35W Denso recommended, or Morimoto 3Five or 5Five to save $)
D2S bulbs (those can run from $50 to $200 depending on the quality and output)
Harness
Honestly, the best thing to do is call Matt at theretrofitsource, tell him serge referred you, and he'll walk you through the entire process.
Are your sure your guy knows how to retrofit projectors?
These are expensive parts to be fumbling around with.