These are Oniscus asellus absolutely, but your first picture definitely appears to be scaber - you can see their granulation, which Oniscus doesn't have.
This appears to be an Armadillidium vulgare. Everyone can appreciate a vulgare. Excellent photo.
It depends where you are located. I don't know anything about keeping frogs, but if you want a species that breeds quickly, is hardy and cheap, then Porcellionides pruinosus will be your go-to. If you don't already have them, I'd also recommend grabbing a bunch of springtails.
All my colonies are wonderful in their own different ways and I am very happy to have them!
I started down the same hole a few years back and now I keep 12 different species. It's dangerous.
Hoffmannseggi are one of the largest terrestrial isopods available in the hobby, so this is very much on the upper-end of the spectrum. Generally speaking most common garden-type species will average somewhere about 1.5cm long, whereas hoffs can hit 4cm! There are other larger species such as some in the Tylos genus, but they're not something than can be captive bred - much like the deep see king of isopods, Bathynomus.
When people ask what I like I still open with: "it might sound odd, but it's [woodlice]."