Nice thing about the reflector is you can lower the intensity for veg, allowing your plants to stretch a little and also saving some electricty, then pump it up for flower to full strength. For a 5x5 area I would definitely go with 2 lights, the you can angle them slightly to get better penetration and also if one dies, you arent SOL. Consider 2 mars reflector 144*3watt. Cost will be around 500, depending where you shop. Make sure you purchase from a legit seller so you get the 3 year warranty. Another consideration would be the cidly apollo 10's, 2 of them would cover that space well and would run you around $600, probably a little better light, being modular and allowing you to customize your spectrum at no additional charge.