Any radio can be wired up (if you're willing to cut/splice wires), but there is not enough room in an MJ dash for the larger sizes of radios.
I forget what it stands for, but a "DIN" is the size of a standard radio. Roughly 2"x7". A 1.5 DIN would be 3x7, half-DIN would be 1 x7 and 1/4 DIN is 1x3.5". My little eqalizer is a 1/4" DIN size.