I'm not sure if you are asking for a different version of marked cards by penguin or another type of card that has more subtle marks.
In the first case, I don't think that Penguin has created different versions of the marked cards.
In the second case, you could consider the GT Speedreader deck (Penguin is out of stock but I found on on Amazon). Or, if you are looking for more subtle marks, you could go with a coded marking like the Deland deck or Bicycle glider backs.
In closing, realize that even if the marks are large on the marked cards, you only worry about because of magician's guilt. No one is going to notice, if don't point directly to them.