I do own a BC14, but DO NOT own a par 38, but I don't think they would spread the whole tank. 2 Ecoxotic panorama pro modules would light up the tank perfectly and be under$ 200, it is what I use on my tank and love them. With the Ecoxotic lights, I was even able to keep the stock hood with the setup, it dropped the temps over 2 degrees as well.
Actually i ran a par 30 on my biocube 14 and it was more than enough light. I did 40 degree optics and ha the light Aprox 14 inches above the water... If I did it again I would probably do 60 degree optics. It's definitely possible tho