what kind of tubes are you currently using? depending on how many Catts you have, i would probably just supplement your current lighting with some strategically placed CFLs.

I have exactly the same setup as far as shelves go. I have catts and laelia's primarily and have no issues with growing either. (I also have phals, phaps, zygos and vandas - no, I can't make up my mind!) I have shelves spaced at 15, 18 and 23 inches to accomodate the wide variety of plants. On the 15/18 inch shelves, I run 4 40w t-12's - two 5k and two 'wide-spectrum' 3.5k's. Anyone who says you don't need the red lights to promote flowering has not done their homework. I ran 2-5ks and 2-6.5ks on the shelves first with no spikes/flowers. Since I switched to this mix, I have at least four plants in spike.
On the 23 inch shelve, I run 3 sets of t12's. 3 wide spectrum and 3 5k's. I am trying one shelve with all 6.5k's just to see what will happen - but I am pretty sure I know already. The 'newer' lamps in the 6.5k range are true 'full spectrum' lights and should replace the mixed.
I also have a 125w cfl over a number of plants too and I am very happy with that. Much more light from the same wattage, but not as large a coverage area.
There is no 'perfect' setup, so much depends on your spaces, plants, available light, ect, that the 'perfect' setup for one person may not work at all for someone else.
So to enhance light to your setup, you could:
- Add some t12's to your existing ones or
- Switch to t8's which put out about 20% more light or
- Add/switch to CFL's.
65w CFL's are about the lowest you'd want to look at - simply not enough light with anything less and even the 65's are not powerful enough for large catts. In order to reach all the way down those tall babies, you may need to look at the newer 125 or even 200w CFL's.
I have about 300 growing under 24 different lights - so I have a pretty good idea from experience what will work. Hope this helps!

OK, that's great. Now, I am electronically challenged so could you tell me what is a 3.5K & 6.5K? Is this where you get your red light? Are these fluorcescent bulbs? Where do you by you Compact Fluorescent Fixtures? Thank you so much.
My headache is starting to go away.

Sally,
I'm pretty new to this stuff too, but I'll try to answer some of your questions.
3.5K and 6.5K is actually the color of the tubes. It is the color material has at that temperature in Kelvin degrees. The lower numbers 3.5K are red colored. The higher numbers 5.5K-7K are blue. These are all fluorescent. You can get up to 42W CFL at home depot or equivilant. If you want higher wattage check out topbulb.com or search the internet.

Hope this helps,
Chris

most 42W CFLs are available only in 2700K or 4100K. according to some information posted here and elsewhere, all fluorescents are "full-spectrum" to a certain extent. so bulbs marked with a lower color temperature may actually work just fine.

What Chris said!
As far as buying, I bought my first CFL at a local indoor gardening shop. Bad mistake - paid WAY too much. Now I buy everything on either Stealitback.com or ebay. I've bought a number of good lights from both.
My plan is now to get some LARGE hoods without fixtures (there's a number on both Ebay and stealitback) and put CFL moguls into those. The mogul is the base for the lamp itself. To answer one of your questions about CFL's fitting into regular lamp bases, yes, for the smaller ones. The larger ones can be used either with a mogul designed for them or a mogul that screws into a regular base.
For CFL hoods, keep in mind that the base has nothing to do with the wattage you can use. You'll see hoods for CFL's recommended with a wattage, but as long as the lamp fits, it will work.
For shelves, I don't know that CFL's are necessarily the way to go. My CFLs are all over tables, but I am setting up a shelve unit now with 3 x 65w on one shelve and 2 x 95w on another. One of the disadvantages of CFL's (at least in shelve use) is the light coverage area is square while shelves are rectangles.
The $7 HD unit (I've been to 3 HD's and never saw a T8 fixture less than $30) would be ideal. Use 2 or 3 of those per shelve.
Hope this helps!

I fit my CFLs into an HID hood I purchased from stealitback.com for $1.

Pictures:

Since my CFLs don't require moguls or have remote ballasts, I simply screw them into the socket through the hood with a thick rubber gasket in between.

Sam