I would recommend 4 or 5 5000k PAR38 LED Lamps like philips 5000k 19.5 ambient LED @ 1300 lumen per lamp for vegetative growth.
Will put out as much light as 70 MH.
They worked very well in a 2 X 2 X 4
Pic of area with 5000K lamps on...
Plants set to flower cycle with addition of philips greenpowerLEDs and 5000K lamps last week.
Pic with all lamps on.
4 - 19.5 W 5000K lamps
4 - philips W/DR lamps
1 - philips FR lamp
166 W replacing 2 - 70W HPS @ 180W. Best part limited heat.