Broadway Cafe is certainly known for pretty good latte art. I would also throw Espresso dell'Anatra out there. They take some of the best pride in the presentation of their coffee that I know of - http://www.kcperky.com/2008/02/12/cof... .
I only know of one place in the city with a clover machine- The Roasterie Cafe in Brookside. I have the ethiopian beans on the clover- its great. A barista recommneded an "aged-bean" they have made on the clover. it sounded good.