Question about how to list multiple items in one listing (see explanation)

[wes3936]

Hello.  Thank you in advance for your assistance.

I have a set of baseball cards that has 100 cards.

Within that main set there are seven subsets (Base, The Rookies, American Pride, Rated Prospect, Elite Series, Dominators, and Now Playing). I want to create a listing where they use one dropdown menu to select one of those seven subsets.  Once the subset is selected, there is a second dropdown menu the has all the cards/players available for that subset.  So they would click on that dropdown menu scroll down to whichever players card they wanted to look at, and select it.

I tried doing it under a variation listing with the subsets as different attributes and listed the cards under options for that attribute, but that didn't work, it created like 90k possibilities which it said I had to reduce down to 250.  I know its a simple answer, I just can't see it.  Thank you.