I did my 03, go to the tech thread look up my old post all the part numbers are there. Biggest problem is the wiring harness for the bed cover light, that is listed on this forum under dome light for cargo area I believe. This was a great option, but like you I ordered the first one, and had no info on the bed. I think the sales manager I talked to at order time said it was wood strips in the bed. When I finally saw one with this option, had to have it. All the parts cost around $1000 but priceless! If you do this PM me and I will give you all the installition tricks, I learned.
Installing carpet,bedstrips,cargo cover trim, and light
Just finished installing the bed carpet and strips, and the cargo cover trim and
light. Thanks for all the part numbers and helpful hints especially on installation
of the wiring harness.
The Chevy dealer was totally clueless on all the above.