The one that says "BLOOM" on it.
That's what it comes down to. What you can afford, and the brand that strikes your fancy.
Many people have many different preferences, and preferred "Systems" ... that's where you buy a bottle of each in the line up... which means half a dozen bottles of assorted additives & stuff + the bottle of bloom.
Since your asking questions... you might want to Keep It Simple this time around, and decide on one bottle that says Bloom.