Hey roger,
General rule of thumb for proper leds is 30+ watts per ft2.....so for your 4x8 your gonna want 2 x 480w drivers for 960w across the space at a minimum, you can go with 2x 600s and dimming capabilities if you want, obv up to you. I will use 480w drivers for the math.
The strips you linked are 2`ers, ran at nominal are good for 13.6w per strip, so if my math is correct
480/13.6 = 35.29....so anywhere from 36-40 2`strips per 480w driver will have you running at nominal or a touch below if im not mistaken.
Im gonna stop there and let the smarter dudes help with driver pairing and all that jazz, im still trying to learn all of that stuff myself lol.
@Chip Green
@Rocket Soul
@1212ham
@Moflow
Ill tag a few of the guys i know are much smarter than i in this area, hopefully they can come along and clarify shit for you that i cant lol