I have an ancient 32w 6000k t12 on my tank (it is also a 55) and a little sun exposure through a window full of plants. I'd say you have medium light plants, which is what I have and they are more than happy. Just look around the house and see if you have any spare fixtures. If the fixture you use is not designed for aquarium use, either hang it high above the tank or find a piece of glass or acrylic or even saran wrap and put it underneath. If the fixture you use doesn't have a reflector, the best reflector would be a space blanket, next to cut one off of an old fixture, and finally, if you can't do either of these, use aluminum foil. The reflector is almost as important as the light itself. Even just painting the underside of your lid white can give you1/3 more light!
As for the eyesore, my tank is built into the wall, but any light will look good if you make it a wooden, or even cardboard box. You can use a long flowerpot or two, like they make for windowsills to cover the light. These sometimes come with nice patterns on them