Definately a 600 watt, i think 1000 would be overkill. If there is space try and have a veg and flower room so you can put clones from the veg straight into flower with no delay and see a nice yield every couple months. I also hear air cooled lights are the sh*t ! If i were you id grow them to the end inside as you can easily control the plants variables, temp,water,pests, nutes.

Charbud