What light design and type should I use?

Im growing in my closet with tinfoil on the walls its 8 feet tall and about 3 by 4or5. I am going to use either a Hps 400 watt light for all stages of life. Another way I will do is Using a 2 light 40 or 42 inch light and its fluroescent. How many watts should i use I am probly going to grow around 6 plants for my grandmother. She has Alzhiemers and Dementia and lack of hunger. Would this work please be professional.This is also my first growroom.

You shouldn't use tinfoil it can cause hot spots. I would get a conversion bulb(mh/hps) since your space is limited.

600 watt digital dimmable HPS/MH is your best bet

Typically people say that a 1000 watt covers a 4'x4' area. So really, a 1000 watt dimmable, or 600 watt bulb will handle your area sufficiently. Exchange the tin foil for mylar or polyfilm, or you can just paint the walls bright white. Personally I would go with a dimmable 1000 watt because you can dim down to 500 watts for vegetative growth, then flip to 75% or 100% for flowering. However, you may need some type of air-exchange and or ventilation for the heat when running at 1000 watts.