Thanks for the link, MIke - I've bookmarked it for future reference. Looks like all the solutions at that current range require one chip per channel, so that may be the way I go.
To answer your question, fungus, I'm planning an 8x8 direct drive LED matrix with LEDs that individually run on either 100 mA or 300 mA, full power (no dimming). Only one LED will be lit at a time, so total current draw at any time from all the LEDs will be that 100/300 mA figure. Will control it with an Arduino.