I'm not sure that it will make much difference if you have a spring shop either rebuild yours or make new sets... just explain what you are trying to accomplish (ride height and such) and estimate the weight and let them design the package.
If you decide to play with the springs yourself, you will want to clean them to bare metal, mag-check the center holes and the ends of the main leafs for cracks (or even the entire leaf).
Compare each leaf, from the same position on each side, to compare the amount of arch and the length. You will quickly see by the wear spots if one side has an extra or is short one leaf.
If all leafs are in good condition you could simply reassemble and install them after deciding the issue of the leaf count. Springs really don't know where they are installed, in which position or in what vehicle. Unless they have tapered ends that you need/want to maintain you can shorten a donor to fit your needs. The important things to consider are the lengths, the leaf thickness and the amount of arch. Unless the vehicle has more weight on one side (offset engine) then all pieces from both side should be the same.
If you need more capacity consider adding a full length leaf under the main (you can use a donor main leaf, just cut the eyes off) There are some tricks to leaf arch and placement that I learned back in the 'old' days but I don't type well or fast so won't start now. Yes, you can change the arch at home. Be happy to discuss on the phone if ya need.
Gary