I'm also a big fan of the J45, and selling my old one was one of my big guitar regrets. Personally I would go with the Mahogany B/S. It will give you something different from your A320, and you can sunburst the whole body of the guitar (which I believe you can't do with Rosewood?).
I had an all Mahogany American (sunburst) A style made for me by Avalon, and it was a great guitar. A spruce top would probably have made it more versatile.
Also by purchasing a J45 style guitar from Avalon you will get a higher quality instrument. Gibson acoustics can be quite variable in quality from guitar to guitar for some reason.
Anyway, good luck!