gas performance i/o vs o/b ?

[abl1111]

I am trying to decide on a motor, or motors for my 23 Tsunami project. I would like to know how you all feel about this. So, let's say you could put any motor on the back of 'my' boat ( excluding $diesel$ ) - what would it be ? The options are:

(2) 4 cyl i/o's w/ alpha or other drives
(1) 8 cyl i/o w/ bravo II

(2) o/b direct inj.
(1) BIG o/b direct inj

(2) o/b 4 cyl
(1) BIG o/b 4 cyl

(*) all outboards would be on a bracket...

Pls tell me why you would choose that motor - i.e. estimated gph, maintenance, cost for the motors... etc. If you are familiar w/ brackets, add your opinion on that too, pls.

Thx,

Alan