MH or HPS and wattage

ok heres the deal, i will be building a shed for growing my meds, it will be 10' by 10' so i will either have a veg chamber 5'-5' and flowering 5'-5' and have the other 5'-10' for stuff and electronics OR have a 5'-10' chamber with a 1000w hps, but in the dual chamber, what wattage should my hps and mh be? can anyone give me like a watt/square' ratio? and tell me if the dual or single chamber would work better, both will have reflective surfaces oh and as i type this i remember in the extra space there will be a 5' 3' space for clones and sprout lings

storm