No, none of the Dead Space novels feature Issac Clark. But they are very good.
There is even one (forget the name), that takes place long before the events of DS1 and tells the story of how the first marker was found on Earth, and how the unitology religion was founded. Really great book.
But they all feature new characters. But they are still very good.
The only exception (if you want to call it that), is the graphic novel that takes place right before the events of DS3. But it is in painted comic book form, and can literally be read in like 20-minutes.