One important matter that hasn't yet been mentioned, is the response time of your LED's and their current requirements for full brightness.

Can you provide some data?

There's a simple and very old way to do this for under US$2.00 which requires only a handful of the same ubiquitous TTL component (7 pieces, 74LS145, 7445, 74LS42) to drive the LED's. You can easily do it with the port pins available on the DIP-40 part IF you're willing to multiplex on a LED-by-LED basis. If the current requirement is large, you'll need an additional handful (7) of NPN bipolar transistors as buffers, or an equal number of logic-level n-channel mosfets.

Contact me via email for details. Erik doesn't like old circuitry, so he'll be incensed. He's not happy with components old enough to have the paint dry and the price within reason.

RE