Sorry I misunderstood. You said "products" so I assumed you were going to sell stuff.
With the 5x7 thing, would it have an onboard PIC/micro? I guess it would have to unless you use serial buffer chips and dedicated matrix chips.
Assuming it has 2 5x7 displays, it could have 3 modes;
1. serial input 2 ascii characters, then display them
2. serial input a vertical byte (7 pixels) on the far right or far left
3. scroll all data right/left 1 pixel
So they could be joined together and used just as a fast ascii display (like a clock etc) or you could load them with any data then easily scroll the whole display.
I'm not sure how you would address them, either make each module numbered (solder jumpers?) or just shift the serial right through in a smart format, so when you scroll one module left a pixel it sends out its leftmost byte automatcially...