Without addressing which boat is "best" or even if it is appropriate for you or your intended use: when you are talking real blue water cruising, all other things being equal, the bigger the boat, the "better". More room for stores, fuel, water, living space, etc. That being said, I think you are almost always better off buying the boat that is closest to sail away conditition for your intended use. Btw, I absolutely love both of your choices; they are classic Alberg designs. But beware, neither was desinged or built for the open ocean; also any one you find will likely be 40 plus years old. This means that unless you luck out and find a model that already has been upgraded and modified, your new boat will need significant work to be made ocean-ready.
fwiw, I have never sailed on an Alberg 30, but I have heard that they have control issues sailing downwind. Not what you want when thinking of tradewind sailing across the Carribean or Atlantic.