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.