Wiring Harness question

[Chrysis]

I've been doing all the reading and searching I can, but I'm still not sure what wiring harness and PCM I need for my 2005 L33, and if I need anything other than a pedal for the drive by wire? Will an LS harness work, or will I need something specific to the L33?

I Have the 5.3 L33 block, and an 4l60E transmission hoping to find a home in a 69 GMC stepper.

If I'm blind and missed an obvious link, just point me to it and chastise me, I can take it =)

Thanks in advance!