I'm not sure what you call a small space if you are considering tomato's and peppers as small space crops. Florescent may be your best bet in your case, but the light source needs to be real close to the foliage. The Lumen level (intensity) drops significantly the farther it's away from the plants. It is a good thing that florescent don't put out much heat. But with plants about or more than 3 feet tall, I'm not sure if one bank (two tubes) of florescent
lights will give good results.