The pilot and two passengers were on a cross-country flight; about two hours into the flight they decided to land for a rest stop. The pilot reported that he saw some breaks in the clouds below him, so he descended to land at a nearby airport. When the pilot saw the runway, he was too close to land, so he circled to the right for a better approach. The pilot stated that while turning onto the downwind leg he failed to keep enough airspeed and stalled the airplane. He added that he didn’t have time to extend the landing gear. The airplane impacted a muddy wheat field and came to rest in an upright position. Examination of the airplane revealed substantial damage to the engine firewall and fuselage, aft of the door posts.