Can you post some photos of the shots you really not happy with? The fact that you are using a digital is not likely the problem, as most digital cameras will more than match the sensitivity of most films you can purchase at the 'big stores.
A couple of 75 watt house bulbs and a work light is really not a lot of light, at what iso are you setting your camera? (Your sensor really only has it's base iso, all other iso settings on your camera is only amplifying it's output - if you were shooting raw and your camera really recorded raw data then you could do the same iso increase with a raw data reader after you download your camera.)