I tend to use Illustrator more for line art. Whether you use photoshop or illustrator, I use the bezier curve/pen tool for doing line art. That said, if you don't know much about photoshop, the bezier curve tool is going to have a very high learning curve (no pun intended).
You could send me a napkin sketch with measurements and I could probably make the base for you within a few minutes. Sometimes there's a "teach a man to fish" moment.... but unless you plan to do this a lot, it might not be worth it.
That said, you can always look up online tutorials about using the bezier curve/pen tool. That's what I use for line art.