if you are worried about heat then i would go with more CFLs to flower with but the SOFT WHITE, or WARM WHITE...theyare down in the 2700K of light spectrum, perfect for flowering walmart carries 150w equivilents which is like 42w in actual wattage

im using the 70watt HPS out of a security light from homedepot, but there is a website that sells smaller, like 35 watt and 60 watt HPS lamps(HPS=high pressure sodium, the standard for flowering your MJ plants)