Based upon what you described you are looking for I dont think there is a better area than where I live (Encinitas/South Carlsbad) I grew up in the Northeast in a fabulous community and this is the closest thing to it you will find. In your price range for something with room inside and outside I would learn about Olivenhain. In your time frame you should be able to get a 3,000 to 4,000 sq ft home on a half acre lot. It may not be the newest shiniest home but you can take care of that via remodelling if its important to you. You will get mature trees much taller than your home, no HOA or Mello Roos fees, great schools and a reasonable commute. You will be within a 5 to 10 minute drive of everything you need a regular basis (shopping, supermarkets, restaurants, libraries, doctors, sports for kids, great beaches, golf courses, movie theatres etc).
For my money there isnt a place I’d rather be in US. But thats just.