mhenstell:
Trying to position the controller(s) close to the strips. I suppose it would be feasible to use one SPI port and 24 select lines, but the SPI port would need to run at nearly 3 megabits.
That should be theoretically possible right? The SPI runs at a maximum frequency of system clock/2, so that's 8Mhz, and you only need 2.7Mhz. For select lines...I think you can use a 5x32 decoder out of 4028s.