Neither. A 30" cabinet is going to be extremely hard to grow anything in. Why is it so small? If at all possible, I would really try to make this at least another foot taller. You can only keep a plant to short.....
Lighting needs are determined by your sq footage. In general, you want a minimum of 3000 lumens per sq ft for vegging and 5000 for flowering. Lumen numbers should be on all packaging for bulbs. Different lighting has different lumens per watt. CFLs run about 62 lumens per watt, T5s run 92-100 lumens per watt, HPS run 100-150 lumens per watt.
Given you space constraints, IMO, T5s are going to be the best for you to run. They are low profile, they spread the light (and heat) well, put out about 50% more usable light than CFLs, and you can keep the plant canopy within an inch or 2 of the light. You will need to buy different spectrum bulbs for the vegging and flowering period, but you have to do this with whatever lighting you choose. For vegging, you are going to need 12,000 lumens of light in the 6500K range (blue light), for flowering, 20,000 lumens. You will probably want a 2' 8 bulb fixture. Something like this: [ame]http://www.amazon.com/Light-8lamps-DL828S-Fluorescent-Hydroponic/dp/B00NMX5EGC/ref=sr_1_8?ie=UTF8&qid=1428933585&sr=8-8&keywords=2%27+T5[/ame] You also need ventilation regardless of what light you use. Ventilation is not just for cooling purposes--plants need a continual supply of fresh air all the time for proper photosynthesis.
You are operating under a common misconception though--when you get as many CFLs as you need, you WILL have more heat than if you ran an HID. And by the time you buy cords, bulbs, and reflectors, you will probably be in more money than running an HPS. Since lighting needs are figured as lumens per sq. ft. and as CFLs put out the least amount of lumens of any bulbs we use to grow (and they produce the least), it takes 2-3 times as many watts to create the same lumens. Just to give you an idea, a 2 x 2 space would require 13 23W CFLs to give you adequate light for flowering. Also, with an HID, you can run an air coolable hood.
