Looks like I'll need to roll my own to get what I want. :-(
AtomicFE and the layout i did for you doesn't work for you?
Unfortunately, it skews the screen shots. Say I have a 244 x 256 screen shot, it scrunches it from top to bottom, and stretches is sideways.
This really is an easy thing.

Center one game snapshot, with the Game title under or above it. And some sort of indicator to show there are more to scroll through.. Scale the picture up to fill the screen, but don't distort it..
So, basically it would look like the old screen shot area in MAME32, but full screen..