I use tobacco sized penny sleeves in tobacco toploaders from UltraPro - then a tobacco card box that holds 50 of the toploaders. Works great -
https://ultrapro.com/products/tobacc...RoC68wQAvD_BwE
I have seen others put the cards in cigar boxes, which is actually a cooler way to store them, if less space efficient. You can pick up lots of old cigar boxes pretty cheap on ebay.