I called Home Depot about the Peddinghaus anvils, and apparently their "global" warehouse is their online site. In other words: if a product is not listed on their site, Home Depot does not offer that product. In fact, they do all of their ordering for their stock through the same online interface that a customer would. They may special order an anvil if I called their "Pro" department and asked, but I have a feeling that a special order from Home Depot (if even possible) will be more expensive than someplace else who naturally provides the product. That is just speculation, though.
I found some Peddinghaus anvils at https://www.plumbersstock.com/searchResults/?query=ridgid+anvil, and they have a pretty good discount. They ship by freight, which is about $200 for the 165# Model 9, and $260 for the 275# Model 12. I also have a few tool vendors close by that can possibly order an anvil at a much better price, so I'll give them a call before I place an order myself.
Aside from price and availability, I do like the placement of the hardy hole on the Peddinghaus, as well as the upsetting block (although I think the only model with the upsetting block is the Model 12). The Rhino doesn't have either of those, and the Fontanini is definitely more expensive. I'm thinking a Peddinghaus anvil is the way to go, at least for me.