Check Toshiba. They have a broad portfolio of constant-current LED drivers.
Thanks for the suggestion, alas all of the stuff I can find are serial input devices (shift registers with constant current outputs).
Edit:
Okay so I've been thinking about this all day but haven't made any progress. Say I wanted to use something like an ST STP08DP05, how would I get the data from the 74HC5411 into that one?
I've been playing around with the idea of using a 74HC165 parallel input serial output shift register to convert to serial and then use a ripple counter to count the 8 clock cycles it takes for a single transfer and then stop it based on that.
How would I trigger the start of a transfer after one of my other counters in the counter chain rolls over?