Hi,
I also have a 1973 E-27, hull #372. I have had this boat for 30 years. It is still very competitive. First and seond in the last two races.
I have hanked on sails--storm, 100%, 155% (for racing) and a cruising chute--and I sail in the Tampa Bay area. Most days my working jib (100%) gives me all I need. If you will race, you'll need to go for the max, 155%. My loose-footed main has two reefs and a Cunningham. Plus an outhaul. Full battens for the top two and long battens for the bottom two.
Sails are your engines. Don't be cheap in buying them. Get the best your budget will allow. A Ferrari with a Briggs & Stratton lawnmower engine in it will always be a dog.
Morgan Stinemetz