Pyramid a good solid, easy to execute design. I think Hickory needs to be dry (8% or less) to perform really well, no matter the design.
A second option, is the holmgarde type bow, like the Tim Baker alligator gar bow. 1 3/4" parrelel limbs for the first 1/3rd, Eiffel tower taper to narrow 3/8 or less tips. Increasing thickness on the outer 2/3 thirds. Inner third does most of the bending, outer third is a straight lever. That may be the fastest design for a straight, flat bow. Tim's settled at 179 fps after shooting in, if I recall. It don't get much faster than that.
Gabe