Lighting Questions

[orion141]

Hi everyone! I have been lurking for a little while and reading as much as I can, but I have a few questions I would like your opinions/advice one. I currently own 6 cattleyas, 2 phalenopsis, 2 oncidiums, and a paph. I live in a 2 story town house in central/west florida that has only north and south facing windows. As such the lighting in the winter is direct sun coming through the south facing windows starting around 12-1 PM. However during the summer none of my windows really get any direct sunlight. As such I have been considering the addition of a wire rack with some 4ft x4 bulb fluorescent fixtures to supplement my light. This leads me to my questions. Do you find that the 4'x4bulb fluorescent fixtures ( I am looking at the hydrofarm ones) generate a lot of heat for the plants situated directly above (from the internal ballast/lights). Also considering that some of my plants are lower light orchids (paph and phals) would you recommend getting a 4'ft x 2bulb fixture for a different shelf on the wire rack for them? I have just purchased a light meter that should be arriving today to get some better light measurements in my windows. Thanks in advance!