Jereon,

What is the current (or size) of 7 segment LED displays?

You can do it in a cheaper way. If you use CA dispalys, connect all segments (a-g) in parallel, and drive these 7 commoned segments from a port through a ULN2003.

Use 6 port pins, to drive PNP transistors and drive the CA terminal of each display, with this PNP power transistor (e.g. BD136).

Using this hardware, I have used upto 4" size LED displays.
Regarding software, you need to enable one display at a time, use a timer interrupt to scan the displays at say 2.5 msec.
If you can't do it and need code, Please let me know.


Regards

IA