There are 8 lug disk brake kits now. Have a friend who installed
this kit on his GMC 3/4 ton and is very happy with the results. Kit is for 47-59 Chevy/GMC 3/4 and 1 ton models.
The good news is that the link you shared says suggested retail price. When you get to the seller, the price drops to
$680 for the plain Jane setup. I may be able to swap out the front axle to a 3100 as well. That should open some more options too.