Imo, James' idea is the best. Both halves of the card are right there for viewing on the indicator card, and then have the dual face cards in clear sleeves in the SB. With this technique there is no unsleeving, no flipping around. All the info is right there, and the real DFC can be acquired later, during gameplay. I'm very strongly tempted to utilize this technique, especially since I do cater to newer players.
I'd be interested in it too, the only issue is that I have 0 talent at making proxies lol.