I did some checking on this for you and here is what I have come up with, I double checked dealer pricing and aftermarket pricing and availability, and the best bang for the buck is going to be to purchase one roll of 3/16in line and one roll of 1/4in line.
You can purchase a 25ft roll of 3/16in AGS Zinc Plated line as a kit with the fittings you will need for $26.39 and the same in 1/4in for $26.99 from JCWhitney.com. That should include everything you will need as far as lines. However, you will have to bend at least some of the lines. The only lines that are really available prebent for your truck are right and left hand front brake lines and the one frame mounted rear line. Those being the twisty one up front and the other one right beside it for the front and the line that runs the length of the frame on the driver side, but it may also not be prebent, the other prebent lines leading to the back, etc are no longer available.
If you wanted those lines then you are looking for GM part #'s 15711815, 15711835, and 15711830. Check the prices at your dealer but they should be an approximate total of $105 or so retail total at the dealer.
Once you have the lines, when it comes time to bend, cut, and flare them, go check out Autozone's loan a tool and see if they have the tools you need to do the job that you can borrow. You will have to pay for them and be refunded the cost when you bring them back but you are not stuck with them if you never plan on doing brake lines again.
I truly believe this is your best option overall, I hope this helps you get an idea of what is needed.