I reckon you could go with an inch wide handle that is 4 inches long, fadeouts of 2 inches on either side of the handle, then 2 inch wide limbs tapering to 1/2 inch at the tips. Length should be at the very least twice your draw length plus the 8 inches of handle/fadeout area.
To echo another post, where are you located? Chances are we have someone nearby that might even be available to work with you on the bow.
Secondly, what species of ash do you have in your crosshairs?