So Tom;

First do some measurements. How much clearance is there all around your present wheel/tire combination, and actual measurements of the current width and height of your present tires.

Calculate how much wider a 584 tire can be than the 622 tires you have now. If you can only get 1 or 2mm additional width, probably not worth it. If you can get 10mm or more additional width, then worth it.

Also note that you do not have to have the same size wheels and tires front and back......

As 2frmMI did; I recommend Velocity's Cliffhanger rims.