the 400w looks very appealing, especially one for under $150. but does anyone have an opinion about using two 250w instead of one 400w. it's a few more lumens for only 50w more. i figure it would be better light distribution, but would it have the same amount of penetration?

also, does anyone know where to get cheap-er electronically ballasted lights? i know insidesun.com has cheap magnetic-ballast lights, but not the electronic ones.