I usually open the rat pack and then individually baggie them up in "snack bags", I weigh each one and put 3-4 of similar weight in quart bag so that they are all essentially double bagged. I further store them packed rats in a freezer container to prevent freezer burn.
At this point keeping tracks of prey weight is unnecessary but I still record it and feed smallest to largest. Since he topped 1000g he has refused every single rat over 70g, he seems to prefer the 50-60g size. So when I weigh the rats, I set the largest aside and when he refuses them they go out to the crows, I still offer them but to date he's never taken one that size.
I personally don't wear gloves or anything, I've been chopping up and processing rats / mice and other prey for years, so whole frozen rats are no big deal. (I still wash my hands thoroughly after)