max/msp >arduino> multiplex>80 leds

hello there : )

I need max to control approx 80 leds from an arduino.
where 40 or more would need to be on/latched.

I thought perhaps to build a 9×9 multiplex circuit(giving 81 outs) on a vero board, but think perhaps there would be allot of led flicker? So at each of the 80 multiplexer outputs I thought perhaps to attach an electronic latch type circuit: 555 timer or alike, so that a short logic 1 would latch on the desired led. I would need 80x 555 timers with that idea lol. that would be allot of circuitry for my project box ,might be better to buy 4 x mega arduinos.

I just wonder if anyone here has a cool solution in this area, or perhaps direct me to an IC that might help?

thanks for help. : )