Jessica, I am in the same boat as you! I cant make up my mind as to which poi best suites my wife and I. The sennies are most popular due to how many were imported up until the early 90's. They have the rep of being a 1 person bird, but every bird is different. They are probably the most feistiest as well. They love attention. Talking potential is pretty decent from what i understand.
The meyers have a rep for being a little more mellow than the sennie. Apparently they "love loving you." their talking potential is lower than the sennie. I'm not sure as to how one-person they can be tho. They are also the smallest of the poi family.
Jardines are slightly larger and seem to be quite content most of the time... Talking potential is slightly higher than a sennie.. I don't know much about these guys.
I'm leaning towards the brown headed parrot as ive heard nothing but great things from breeders, owners and the like. Altho they lack the flashy colors, they make up for it in personality.
I hope this helps... I'm new to the parrot world, so if anything that i have written is incorrect, please lemme know

Cheers, Bo