I normally advice against using Darlingtons because of their high voltage drop and consequent power dissipation. However, in this case you are only turning on one channel at a time, and the current is only 250mA, so power dissipation would not be a problem.
You could use the UDN2981A if you increase its supply voltage to allow for its voltage drop (1.7V typical, 1.9V maximum @ 225mA). Or use low-side switching with the ULN2803A, which has a slightly lower voltage drop (1.3V max @ 200mA).
Unfortunately, nobody seems to make octal mosfet driver chips, otherwise I would probably be recommending them.