It's just my opinion but I'd go with Big Cheese Rodents or Perfect Prey over Rodent Pro. I believe the feeder quality and packaging are much better and the prices are about the same.
In terms of prey size I'd give the 650g snakes small rats. 750g is usually when I start my snakes on mediums. The 180g critter can take rat pups for now but weaners soon. The 450g snake can take weaners or smalls.