Matt, I agree 100% with Mike. There's nothing wrong with doing things for the experience, and to make them "yours" as opposed to buying a package. I got off base by Dave's comment, asking how much you thought you'd save, and cost was not a consideration in your original post. I like that compact fuse block with the "weather cover" a lot more than the one in my "kit", and with an understanding of basic circuits, relays and conductor sizes there's no reason that your plan won't work. I'd say go for it, and any wire left over will be a starting place for the next project!