I'm also gearing up for my first build from scratch and have thought about getting a premade neck. However, those necks can be pretty pricey...
Ultimately, I think I'll just jump in the deep end and build my own neck, but this shortcut still lurks in the back of my mind:
Has anyone here considered buying a cheap (perhaps even second-hand) neckthrough and ripping out the neck? Maybe get some usable parts, too.
You might have some holes and routes to fill. I think it might be worth it. Thoughts?