Stew-Mac Tenor...8 String?

I've been tinkering with and repairing guitars for several years, and since becoming enamored with ukes a year or so ago have been working on them as well. But I've never built an instrument, so I've been looking in to kit's for my first build and like the Stew-Mac tenor a lot. I've also been itching to try an 8 string and last night the thought popped in to my head... why not build the kit as an 8 string!? I imagine the headstock would have to have a piece laminated to it to get it thick enough for the tuners, and the nut and bridge would have to be modified and probably enlarged, but to my eyes it looks do able. Has anyone here done it, or have any thoughts?

It could be done I guess. You'd need a whole new neck and fingerboard....wider for the 8 strings and much longer head stock. 8 string ukes are usually 1.5" wide at the nut instead of 1.375". Maybe a new bridge too for the wider string spacings and extra tie holes or maybe you could modify the bridge provided. You might also need to beef up the bracing for the extra load.

Thanks ksquine, I hadn't even thought about the fretboard being wider, it's looking like it's probably a bit to ambitious for my first. I think I'll just build it per the instructions and save the 8 string for a later build.