My setup: 400 watt MH , 400 watt HPS, 200 watt (6500k)CFL. My garden area will be 5'x4'x6.5-7'. I planned on using either Mylar or Black and white Poly Plastic to enclose my area but I haven't decided which one will give me the durability and reflectivity I want my side walls to have. I also...