I need help buying lights for my grow cabinet

Hey guys, I have 4 clones(1 PPP, 3 C99) in a grow cabinet(30''x19''x70'') right now. They are growing under 3200 LED lumens of 5000K and 6400 LED lumens of 2700K.

I know that since I have almost 4 sq. feet I need much more light for my grow. My question is what would be a good light source I could give them that won't cost me a fortune in electricity and isn't too expensive.

So far I have though about these
CFL

http://www.growlights.ca/growlights/hid-bulbs/compact-fluorescent-grow-bulb-cfl/compact-fluorescent-bulb-250w-red-2700k.html

http://www.growlights.ca/growlights/hid-bulbs/compact-fluorescent-grow-bulb-cfl/compact-fluorescent-bulb-250w-blue-6400k.html

I would use the 6400K for veg and the 2700K for flower, or could I buy only one and use it all the time and save money? Also how much CFL Watt do I need for my 4square feet grow cabinet?

Next I heard a lot about LED COB and how great they are but I don't understand how they work, they are chips?
What do you install them on if you have to? how much do you need?

I don't want HID or HPS because of the heat.
Thanks guys

I use a 300 w dual spectrum CFL .
Seemed to do alright on last plant but will be adding additional side lighting for the next 1.

As far as cost of electricity and heat they are both extremely low

the one I've got wouldn't suggest it solo for 4x4 coverage

Maybe something like a t5 ? It's similar to CFL in regards to heat and electricity I believe but runs on tube like bulbs (almost looks like sunbed) so would probably give you much better coverage .

Noobs input .
Could be wrong

This is my style of CFL and an example of a t5 style ..

Check out Timber. They have simple DIY kits. The chips are on the heatsinks, the wires are cut and color coded. All you have to do is build a frame, which they would also do for more $.