People post successes using 2700k lamps, but it really doesn't make much sense to me. DISCLAIMER: I AM A NOOB. SOMEBODY PLEASE CORRECT ME IF I AM WRONG!
To paraphrase Wein's law, a light's primary wavelength can be determined by dividing Wein's constant (2.8977685×10[sup]−3[/sup] m·K ≈ 2900000 nm·K) by the color temperature of a light in Kelvin.
In the case of a 2700K bulb, (2900000nm·K)/(2700K) ≈ 1074 nm.
The primary wavelength of your light will be near 1074 nm. If you compare that to a plant's absorptivity spectrum, such as you might find HERE (http://hyperphysics.phy-astr.gsu.edu/hbase/biology/ligabs.html) that's way off the charts. A lot of the energy you're putting into your lights will be completely useless to your plants. You want to shoot for something closer to 440 nm (6600k-ish) for vegetal growth or 670-680 nm (4300k-ish) for flowering/fruiting, as these are where the absorptivity by chlorophyll-a peaks.
I'm pretty sure the toting of 2700k bulbs as being "great for flowering" is age-old bro-science, passed down by cannabis cultivators and seldom challenged.
Once again, I am not an expert. Please correct me if I am wrong. Also, I suck at linking things in forums, so I apologize in advance if I screwed that up.
Oh, and it's better to get larger, higher-lumen lights than multiple low-wattage lights, since lumens don't really add intuitively. This one of those rare occasions where it's actually a good tactic to put all of your eggs in one basket.
