If you want it that wide, can I recommend the pyramid style, where the bow tapers from it's widest point at the fades all the way down to the tips? They're really easy to tiller cause you can just get the thickness down to a constant 1/2" or so (I'd start a little higher and work it down to make sure you make weight), and you just need to shoot for an arc of the circle tiller. My first bow was one of those, out of red oak. Mine was ~2.5" wide at its widest point, down to half inch tips.