1 x 250w would be nice if you can make it fit and CONTROL TEMP.
4x23w would work as well and it would be alot cooler than the 250w.
for lights: fit as many as you can or go as big as you can as long as youre able to control the temp issue.
wouldnt be any good if its too hot.
autoflower plants doesnt care about the lights you use. they will grow regardless as long as you have the lights on constant 18/6 20/4 or even 24/0 if you please.