1) Blackieboo is most certainly not a better name for a cat that Blackiepoo.<quoted text>
Better than Blackiepoo like you said.
Besides, it's up to the owner to decide in naming a pet.
2) That said, both are terrible names lacking creativity.
3) While it is certainly up to the owner to decide the name, one should not give a pet a stupid name unless one is four years old.