Scaling, Strings, & Neck Length

[Troutwater]

Hi, I have never built a guitar before but I am really interested. I want to do something a little different, I want essentially a guitar with a slightly shorter neck and only the bottom four strings. Anyone have any resources for neck length, string guage ratio?

[Norris]

Something like a Tenor guitar? https://en.wikipedia.org/wiki/Tenor_guitar