I started with a 60" BB but sold it because it was not iMatch compatible. I replaced it with a 54" BB from Everything Attachments. The 60" worked well enough but I think the 54" is a better match. The 48" is too small in my opinion.
I bought a used CountyLine 60" box blade from Tractor Supply. The rippers and blade showed no wear, but the yellow paint was faded and there was a little bit of surface rust. Works just as good as a new one but $100 less. I plan to sand blast and paint it John Deere Yellow one of these days. It is also iMatch compatible. I have no regrets getting a 5 ripper 60".