Hi Justin, good luck with your quest. There are 180 cards in this set, and there are only 89 different cards that have been graded as an SGC 40. In fact, there are only 101 different cards that have been graded in total by SGC, and far less by PSA.
It should be fun but it will take you a while. You may have to buy some raw cards and send them in and hope they will get a 40. If I run across anyone who has one I will send them your way.
https://www.gfg.com/baseball/coupon.shtml has a few. (Daves Vintage Cards)
Rick