Without having a weight, he looks like rat pups would be the appropriate size, maybe weaned rats, but I wouldn't jump straight from fuzzy to weaned anyway.
I've been using rodentpro for a very long time and never had problems but I have been seeing a lot of other people say they have recently.
The only other company I've used for shipping bulk is reptilinks but they do not currently sell rodents and I'm not sure when they will. They have been saying "coming soon" for a couple years now lol. As much as I love links, I absolutely would not recommend trying it as a novice BP keeper because of how difficult they are to get to eat new things.