I would recommend going small on the CUC rather than large. If the CUC has nothing to munch on most will die causing your nutrients to go up. Plus, it's just wasteful. Personally I went with a "30gal" CUC to start on my 220. As time goes on I'll add more. Just be careful about adding a bunch of snails and crabs that have nothing to eat. The crabs will certainly eat the snails then.
+1 to the above. I always order from reefcleaners too.