One of the first props I ever had was a Mental Photography deck. It's rough smooth and long/short combined, with blank cards.

I think I am looking for something like this, possibly a Mirage deck, but I want to make sure I am thinking this through right.

I want to do an effect where a deck is shown to be different, then all turn into the same card. Is the mirage deck what I am looking for, short of a deck switch?

Sounds like the Svengali deck to me

It's part Svengali, part rough smooth - I believe it is the mirage.

Yes, it is a Mirage Deck. The Mirage Deck allows you to ribbon spread the cards very easily to show them all different. You can then perform any routine or trick that you might do with a Svengali Deck. The key difference is that you can easily show them all to be different by fanning due to the r/s. I am selling these in my shop if you want to check them out, just go to my website -www.justinismagicshop.com.