Those would work, but you would need quite a few of them. You would probably need about 85 watts per square foot. I wonder why the UK wattages are so low. Since when talking about CFL's, people get confused with actual watts vs equivalent watts, it is probably best to talk in terms of lumens.
2000 lumens sq. ft./21500 lumens sq. m. = Absolute minimum for growth. You won't get much from this, especially after the plant has grown a bit. Not really enough to flower well.
3000 lumens sq. ft./32250 lumens sq. m. = Pretty Good growth. Enough light for the entire light cycle, although your yields may be lower.
4000 lumens sq. ft./43000 lumens sq. m. = Very good growth. Once you pass around 3500, growth rate and ability goes up fast.
Over 5000 lumens sq. ft./53750 lumens sq. m. = Optimal growth. Dense growth in all stages.
Dr. Buds cabs are between 5000-6000 lumens per sq/ft. He uses in his small microSOG cab 5 42 watt (2700K) 2700 lumen bulbs for a total of 13,500 lumens over about 2.3 sq/ft
