I know it sounds so elementary, yet if I'm putting a set together shouldn't I have both for it to be complete?
Yes, its a proof vs business strike. You also have the reverse of 38 and reverse of 40. Do you need them both for a complete set? Only you can decide that.
Let's put it this way, the Franklin set I put together has both a proof and uncirculated P mint half, and I did that because, though they are the same year and Mint, they are two different coins, struck on two different planchets.
That's pretty much how I've gone with it... I had my pages all set until I realized, "Oops... there are proofs from the 30s, 40s, etc." so out with those... have to re-start I guess... Are there any other nickels that are off the grid? (so to speak) BUnc I'd love to hear how you built your Franklin set - maybe in a private if you have time/want to...
KF, possibly you do know already how to tell a proof from a business strike. If not use the Search button to check out the differences in proofs. You would be surprised how many post here defending their coin as a rare proof because it is 'Shiney'.