Re: new 120% genoa
John F, My 4 cents.
7 years ago I was faced with the exact same question. New boat (to me) bag of rags for sails, desire for beer can and some club racing and Narragansett bay area cruising.
I bought a new dacron main, higher level fabric from an off shore source and the following year again a high quality dacron 135% jib, sourced offshore.
What I got were and still are very good working sails. I still win an occasional race and are always competitive. I make far more tactical and brain fart mistakes that faster sails would not correct.
That being said, Don't do what I did. Get the dacron sails but get them from a local loft. Make sure they come with check out from the sailmaker so you can learn from him/her how the sail is supposed to look and be trimmed at differant points of sail. You can gain a weath of knowledge that way not to mention having a service outlet should problems arise. The little bit extra you pay will be worth it.
Funny thing about leech curl, I constantly battle leech curl on a port tack, no problem on starboard. Haven't figured out why, I just send a guy down to adjust the leech line.