Been there done that, I used with much success a 150 watt set up it worked like a charm you could go 250 watt but watch the heat its always a problem and make sure you check the reflector size and ballast setup its a bitch when you spend money and it's a pain to work with. you will need a air circulation setup 24 cfm will move the air once a minute through your setup. Start right and you will be rewarded.