Here's my setup. It's 5 foot long and I have 6 CFL bulbs 5000k 100 watt equivalent (23watt). Price wise they are not very expensive (https://www.1000bulbs.com/category/100-watt-equal-compact-fluorescents-5000K/). The problem with CFL bulbs is the plants will tend to grow towards them instead of straight up. So spacing them 12 inches apart will give you some very bent plants. You also will need to keep the lights quite close to the plants (within 3 to 4 inches). Even with mine spaced as they are I have to turn my plants every week. With tubular florescent bulbs this problem is lessened but the light output is also unless you use T5 HO bulbs. That's not to be said that it can't be done with T8 or even T12 bulbs as many have had great success with them. The advantage of CFL bulbs is that you can achieve a greater amount of lumens per watt hour and per square foot (although LED technology has surpassed the efficiency of CFL, just not the initial cost).