I'm thinking of doing a very similar thing, but gona start with seeds first, I won't be mothering any of the girls in my current grow. The lights and space will be fine for a mother depending how many/what wattage lights you use. I personally am not going to use cfl's or led's because i'm on a tight budget and with all the bulbs + fittings it actually works out more expensive than just getting a 250W MH or broad spectrum HPS. Of course the CFL's + LED's are cheaper to run and last longer, also no problems with heat which is important in a small space. So if you wanted to use HID lighting you'd most likely want to raise or get rid of the shelf. What are you doing for ventilation? I'm probably gona use a couple of 12V computer fans.
Happy Growing
The Cannabist