Hey Dan
My thoughts and simple credentials. Have sailed out of San Diego for 16 years. I have a 2004 420 Passage. Before that a 336. 23 trips to Catalina, three to Ensenada and one to Cabo. I have no database on Oceanside or any marinas there, nor to I particularly care for that Harbor, but that is just me because I fly in to visit our boat frequently. So many good choices in San Diego but a 45ft slip is gonna start at around 850$ unless you go south under the Coronado Bridge.
The big CC's of Hunter are great coastal cruisers. They are fast motoring and have great range, which is a must on the California coast if you want to go anywhere. You only get fuel once in Avalon before you say never again! Sailing wind is typically an afternoon thing. The aft cabins make the CC's a true apartment on the water. We host couples, which means four of us to Catalina Island frequently. Most of our friends are sailors or RV ers so they know about conservation and tight quarters. The CCs sail really well but require a different mind set than most others with aft cockpit experience. Our boat for instance. In more than 12 knots true or so, it just sails better with a reef in the furling main. High center of gravity IMHO and our days of tacking around the harbor are over. Some say nay to this but they go downwind just fine. Whisker pole or a good broad reach with WIND! We also have an Asym which is an additive to that solution. If you find one with AC put it high on your list. I personally wouldnt sweat a Genset. We have 520 watts of solar and 400 ah of lithium which survives the coastal gloom in the am of Cali with no problems. AC running on the dock in summer during boat chores is just WOW! The big CCs have tankage and great storage. Drawbacks, the cockpits arent that big, but we use the "back patio" as square footage. This is not a sports car. More like a Buick.. Make sure it has a good auto pilot because although light to the touch when sailing, they are a monster to hand steer at 2800 rpm. We completely love ours but people say that about their house when they are trying to sell it.
Cheers and if you can buy one in a slip in San Diego, you can probably keep it there.