Currently in the process of building up an internal gear gravel bike for a friend, I didn't find many prebuilt wheel options for the alfine hub. In his case that's not as big a deal, he's a fairly large rider so its being built with 36 spokes, 3x, alpine spokes, and heavy duty Light Bicycle rims with angled spoke holes for the rear. Even then the hub doesn't come with the cable stop, axle nuts, dropout alignment washers, a cog, or any form of shifter. Microshift offers a drop bar shifter for Alfine so that's where we went being a gravel bike. You're idea of a damaged motobecane for parts isn't a bad one, not sure the ratio of damaged frames to damaged wheels but if the wheels are solid you could have a good setup.