Whats it take?

[98chevy1]

I'm new to the sight and i'm interested in putting a LS based engine in my '98 4x4. I'm thinking on going with a 6.0 but my concerns are;wiring harness, would it be easier to go with something like what painless wiring harness offers or use stock harness? and as for the tranny, could i keep the 4L60E in with out shifting issues? What headers can i use with out spending hundreds on them..like less then $350? Are there any helpful books or articles out there? Any otheir need to know info would be great! thanks for your time. I;m looking for most cost efficient way