I have a .480 Ruger and really enjoy it. I do wish Ruger would release it in a single action though. They did release it in a No.1 rifle this past year so it isn't exactly dead. I do not know of anyone currently listing them in their line up. You could buy a BFR in .475 Linebaugh and then shoot the .480 Ruger through it kind of like the .454/45Colt or .38/.357mag.
If you are a reloader you can have some fun with the .480. I like to load 400gr cast bullets from target loads of 800fps all the way up to 1200+fps.
If you are not a reloader then I would say stick with the .454 Cas.