I would think so, I've forgotten the exact way to work out the sump volume, but you basically have to find out how much water volume would go from the main tank to the sump in the event of a powercut and then add a little bit - there's probably a calculator around
While not the greatest geometry (thin front to back), a 55 is big enough for a sump on a 150. I'd prefer one with a little more width, but you can definitely use it