If you go with 1, it has to be centerline in the boat.......2 are usually on the outbound sides........call seakeeper, they can tell you and are...
That size range isn't going to meet your needs, especially a 28' . A 32' center console is a 10 adult boat (maximum) to spend more than an hour...
BTW. I am NOT your brother (Thank God), and I don't get drunk.
Only your opinion matters....but your opinion is based on smaller boats.... 1" of bilge water that's 1.5-2' wide and 20-25' long adds up to more...
But you always have a wet bilge over many feet of the boat, and that humidity just radiates up and goes back into the boat. Forward bilges on all...