I am Sunset zone 17 as well.
Regarding the apples, I started questioning the low chill limitation after visiting an apple farm that is in a coastal valley about 10 miles from where I live. They grow probably 30-40 different apples, none of them what we would classify as low chill varieties. Their apples include: Gravenstein, Gala, Burgundy, Laura Red, Ida Red, Mollie’s Delicious, Tohoku, Empire, Mutsu, Elstar, Jonathan, Hawaii, Jonadel, Bellflower, Redgold, Golden Delicious, Chieftan, Braeburn, Nittany, Criterion, Mohawk, Jonalicious, Red Delicious, Northern Spy, Russet, Spitzenberg, Calville Blanc, Black Amish, Honeycrisp, Red Yorking, Turley Winesap, Limbertwig (not sure which one), Stayman Winesap, Fuji, Rome Beauty, Heaven Sent, Little Gem, Splendour, Tydeman Red, Newton Pippin, Pink Lady, Chesapeake, Granny Smith, Black Twig, Sun Crisp, Sundowner, Lady Williams. Then I found this information. I was wanting to learn how to graft anyway, so I started an apple FrankenTree. It’s about 3 feet tall and has 10 different varieties grafted onto it. It’s still really young so a lot of the scions I grafted on it are less than two years old and haven’t fruited yet. But the tree was Gravenstein to start with, and it does bear yummy Gravensteins every year. I recommend grafting multiple varieties onto one apple tree as the way to go if you want to try out new varieties.
As far as peaches go, my favorite peach variety of all time for both fruit and flowers also happens to be low chill. It is called Red Baron. Here is a picture of it in my yard: https://growingfruit.org/t/back-yard-landscaping/27491. It hasn’t been in the ground long, but I got peaches off it last year and they were excellent.
And lastly, are you sure your chill hours are less than 200? Chill hours are generally defined as between 32 and 45 degrees F. For years I was given the wrong information by nursery people who told me chill hours were below 32 degrees. My chill hours here are usually in the 250-400 hour range. UC Davis has Cumulative Chill Hour Data compiled from stations throughout California.