H'lo Max, welcome! I noted you posted the same question a couple of weeks ago, but got no response. That's probably because the same topic had been recently discussed at some length. A quick search turns up these threads among many:
What Size Genoa (you posted in this thread, found no answers?)
Jib vs. 150 Genoa
Sailing Main & Jib
Sailing Upwind
Also, don't forget that adding mainsail controls, and a mid-reefing point are just as important - maybe more important to having fun in our boats - than a fancy headsail.
The short answer ... I knew I didn't want a 150 on SF Bay, so I ordered a mylar 135. It's still probably too much for the majority of my sailing, but it's nice to have when trailering inland or going off SoCal's coast. If I was going to stay on SF Bay, I might rather have a 125, but the 135 is a great compromise. More importantly, ask the sailmaker to consider the leech-length carefully. Mine is too long relative to placement of the Genny tracks. This makes it tough to really flatten the sail (see below). I wish the clew was a foot higher, for better leverage from the cockpit's coamings.
Fair winds!
