check out the CRUTCHFIELD website
fill in the vehicles info & a list of radios will be on the screen
on the left side of the page, you will choose which options that you would like to have
some will read FIT, which means it is a 1.5 DIN radio size, which your Ram uses
some will read MODIFIED FIT, which usually refers to a DOUBLE DIN size & that means that if you want to have that radio, you will have to do some modifying to make the hole a bit larger.
several people have done the trimming to make them fit
I've also been curious about this. Not necessarily at the immediate moment, but in a few years when the RHB's look terribly antiquated in comparison to the technology available.