Single standard fluorescent lamps (specially those lower than 40 watts) rarely get warm enough to harm the leaves even when they are a couple of inches away.
Obviously, if you use gang type setups (2 or more lamps) then it will get warmer than a single lamp.
The wattage for standard fluorescents increase with length. The common values are 15w for a 12" lamp, 20w for a 24" lamp, 40w for a 48" lamp, etc.
If you have a light meter, you can measure the distance from the lamp to find out where you will get the 1000fc-1500fc reading.
For comparison, my lighting setup uses two pieces of 20w fluorescent grow lamps and I get a reading of 1500fc about 5" directly under the light fixture. At 10 inches, it drops drastically to 800fc.
If you cannot achieve the 1000-1500fc light, then you can compensate by giving the plants longer light exposure.
For example, if your goal is 1500fc for 8 hours:
1500fc X 8 hours = 12000 fc-hours
If your lights can only give 1000 fc, then you will need to calculate how long the lights will need to be on in order to achieve 12000 fc-hours.
HOURS = 12000fc-hours / 1000fc
HOURS = 12 hours
So giving your plants a photoperiod of 12 hours at 1000fc achieves your target of 12000fc-hours.
This is just a rough estimation and is by no means an absolute law.
However, on the flipside, you DO NOT want to give a plant that requires 12000fc-hours 6000fc for 2 hours or 12000fc for 1 hour
John