I just saw John Turturro playing Monk's brother recently. He'd be good as Howard.
That was a great episode of MONK, of which I am a devoted fan. Turturro is a wonderful actor.
Turtorro and Shalhoub did a movie together, about two New Jersey brothers who owned a restaurant. It was a nice movie (wish I could think of the title--it was made about ten years ago). So I think those two have been friends for a long time.
OK..I looked it up. I googled the two of them together. Actually they have made several movies together and did a Broadway play together, too.
(I am helping to run this thread to 15,000 posts.)