The rule of thumb is 4 square feet per chicken in the coop and 10 square feet per chicken in the run. You will have 32 square feet total in the coop and require 24, 64 square feet in the run and require 60, so, yes, you should have enough room for 6 chickens. These are rules of thumb and not hard and fast laws. It is very likely you will not have space problems with six chcikens but they are living animals with individual personalities. There are no guarantees. With that fine print legal disclaimer out of the way, I actually think you should do very well with those sizes for six chickens.
It depends a bit on how you build the coop, but if you have it well ventilated but with the chickens not in a draft, I see no reason to have a light bulb for heat. I think you will be much better off handling things passively with insulation instead of getting them used to extra heat then having the electricity go off. It is also a little breed dependent, but chickens can normally handle cold much better than heat.
Good luck!
ps: Welcome to the forum. You are likely to meet some nice people here.