BTW.... the Signatures, which are a step below the 20/20s, aren't bad if all else fails. A friend of mine has a pair and you won't lose much going with them. They are also not nearly as imposing physically as are the 20s. Way less $$$ too.
Silverline Sonata IIIs can rock too with not much more amp than the McC, or with it. I'd feel better with 200wpc however, but if levels are maintained with some degree of sanity, the McC + IIIs should prevail very well.
Do look for later models of the Sonata IIIs though... in the past 2yrs. or less.