600 watt hps??

hi everyone i need some questions answered about my new set up, ive got a secret jardin 1.2 by 2 m tent set up and the temp inside with nothing in it is hovering around 17 degrees.

im not sure what kind of light setup to go for wether i will need a cooltube or not? its going to be a 600 watt hps and im gonna have a 6 inch ruck extraction fan/fiilter but im not sure wether i should spend the dosh on a cooltube or just get a light and reflector?? will the temp be ok with the light and reflector or do you reckon ill need a cooltube.

yer but will the temps be to low with a cool tube and a fan system if my temp at the moment is 17 degrees??? im debating what to buy its a pickle cause i dont wanna spend a bomb on a tube and find out its gotta go u know??