Welcome to the Ericson clan!
I believe that you will find that your sailmaker will need exact measurements from your particular boat. That's because it's common to find undocumented rig changes, either from long ago when it was spec'd out for the original owner or from changes that subsequent owners did.
There are sail measurement doc's online and I used to refer folks to the one at UKSails, way back when I was selling some sails from them.
You need a good tape, and usually closeup photos of the gooseneck area and the outhaul area also. The sailmaker will do all of this when he/she builds a quote.
Of course, with basic brochure info, a sailmaker can give you a "ball park" figure.....