Hey guys, a little late to the party on this. But have you looked into Thunderstone? Its a deck-building game very similar to Dominion. You recruit heroes to your team by buying them from the village and each hero can be upgraded to level 2 and 3 from its previous level. However once all the Level 1s are gone you can then buy the Level 2 heroes below them for slightly more money. Might be something to look at for your Pinball game, I do like the idea of trying to shuffle variations into the shop decks.

Great Episode, ~Danny