This is a little more complicated than it sounds. As i see it, and i could be wrong, there are 4 main criteria for a spoke;
Thickness - get this wrong and the hub and rim holes will need to be drilled out or the wheel may buckle if too thin
Length - get this wrong and they just won't fit
Length of thread - get this wrong and there will be thread showing above the nipple or you won't be able to tighten the spoke up
Angle of head - another "won't fit" issue
The head angle and length will normally change on a single wheel so from the (36?) spokes on each wheel you would end up with 18 of each kind. Even with two wheels with the same diameter the hubs are nearly certainly different so you will need to have all the measurements for the 4 types of spokes you need. Just to make sure. It is a long way to take them back if you have issues.