closet light help

im currently starting an indoor project and planned on using 250 w HL for vegging . The local store that sell s MHL bulbs just sell an ignitor and a regular ballast. It does not include a fan or anything else. I wanted to know if i use the regular ballast they give , is my bulb going to be to hot. How do i solve this problem? can i just put fans in the closet wiht in intake and out of fresh air?
also if im using 250 w MHL bulb for vegging..... what amount of Watts in HPS bulb will i need for flowering?
thanks

MH doesn't need an ignitor...only HPS use em to turn on.....You're gonna need some ventilation....air movement and injection of fresh air.....heat will be a problem without proper venting.....good luck.