Screw in type bulbs are incadecent bulbs. They are designed to light a room with minumum wattage and intensity. PC/VHO/MH bulbs are designed to put out as much wattage and intensity in the smallest bulb possible to encourage coral growth.
You could keep various types of mushroom corals, Green star polyps, yellow colony polyps, some leather corals. There are lot of low light corals, just do some research. You culd also keep non-photosynthic corals such as sun coral. These corals need untimate quality water though.