All Cubensis are about the same strength - some a bit stronger, some not quite so if you are going to grow one, find one that grows more easily in the conditions you intend to provide. Now some strains have more or less bayosistine (spelling) and I personaly don't like that particular chemical so you might want to try to find one that is low in that compound.
there are other strains that are far more potent but they are harder to grow. You would be wise not to fall into the "I want the strongest" trap, especialy if you are growing your own - I mean what do you care if it is a little weaker, then eat another one - you can always grow more.
Do you select your beer based upon alcohol content? your rum? your wine? Do you only eat food that has the most amount of calories in it? or are there other qualties that go toward a complete experience?