Chula Vista had available moorings in your size range last time I checked. As did Harbor Island (can't remember the name of the exact marina). HI was about 40% more expensive but allows you to use your boat
as a down town weekend condo and is 40+ minutes closer to the open ocean (Chula Vista marina is hidden down a long and fairly narrow channel).
Might want to check out the brand new marina at National City too.
Personally I'm in CV and I like it. There are people around me who have done and are about to do intereting things with their boats, from restoration
projects to extended world cruising. Helps keep me inspired.