You can reuse most of your existing brake lines. For the front, you would get two 42" or longer 3/16 brake lines to run from master cylinder to your existing proportioning valve. You can add safety loops and usually avoid the need to cut and flare. Then on the spring buckets, there are two 1/4" holes where 2005-07 SD rubber caliper lines can mount. These conveniently have 3/8 flare threads for 3/16 lines. so you would run two new lines, one from each of these rubber hose ends, over to your proportioning valve.
Then at the rear, you would use your existing frame mounted line and there are a number of ways to do this next part but I like using one of these adapters at the end of the existing brake line works well:
https://www.summitracing.com/parts/ear-989543erl
Then a 3an russell brake line. These have the nice rubber coating and are DOT approved
https://www.summitracing.com/parts/ear-989543erl
then one of these adapters at the axles
https://www.summitracing.com/parts/hse-342-03-03
Then 3/8 hard line to the caliper hose ends, then 2005 (and I don't know what all other years, maybe several) rubber caliper ends)
and you can weld these onto your leaf spring perch to secure the line under the leaf area if needed