The factory beams are 7/8 kingpin on that truck, which is fine for a light duty prerunner.
If you are hard on equipment upgrading to 1" kingpin may be a good idea.
Both beams would need to be bent for alignment at a higher ride height (Autofab does this) and possibly plated to reinforce them depending on use.
Don't let the looks of the beams make you think they are weak.... they are surprisingly strong.