the more light you supply the better... i have a feeling that the side lighting is a waste... good intentions and idea for sure.. but depending on how close it is to the plants themselves they may just be using more energy while no supplying much usable light to the plants... floros dont put off many lumens to begin with, and have little penetration power.. so unless they are within, oh say 6 inches of the plants, they are more energy spent in elec than the lumens they are providing to your girls...
if you can, and do have the funds, increasing the size of the lights you are using will greatly help... the more available light the more growth that can take place... even a simple bump up to one size bigger will help.... or if you can add a couple more lights you can keep closer, that will help out also...
and if you go to buy a MH light, skip the MH and get an HPS.... for a couple reasons.. 1, you can get hps bulbs with enhanced blue spectrums.. which help increase the growth during veg while using the hps, over standard hps bulbs... plus they put off much less heat than MH bulbs...
if you want to stay in the realm of low heat and keeping with floros tho, may i suggest this
http://www.wormsway.com/detail.aspx?t=prod&sku=SSG104&AC=1 these are sunleaves satellite IV high output floros... they are amazing... 420w per fixture... 4 bulb set ups.. each bulb puts out 11,000 lumens.. thats 44,000 lumens total per ballast... they put off almost no heat.. the hottest they run is 90 degrees... you can keep them damn near on top of your plants... i have 4 of these and 2 x 400w hps.. and have better results with the floros so far than the hps.. i dont have to worry about light bleaching or heat stress at all.. in fact i am flowering right now, and have these lights less than an 1/2 inch from the colas, with NO signs of burn from them... they are a bit pricey.. but are well worth it when you dont have to worry about heat.. and efficiency is great as you can keep the light very close to your plants... you can get gro and bloom bulbs.. but would be more than fine just running the bloom bulbs the entire grow.. and i think each bulb is rated for something like 10,000 hours or more... if you want to check them out i have plenty of pics in my journal (links below in sig).. you may have to scout around to find them but you can see what they do from start to finish if you do.. or you can check out the last couple pages as i recently updated pics of my girls flowering....