I recently made one in which the riser was 16" from fade out to fade out. The depth of the riser really doesn't matter and you can just size it to suit the size of your hand and what might feel comfortable.
For a 64" bow that draws 60# @ 26.5", I'd guess that you'd need a total stack of 0.525 with 0.005 total taper.
Lamination order doesn't matter, but it's much easier to glue it up with a thin lamination going up and over the fadeouts of the riser and thicker lams on the belly which don't need to bend.
Something like this....