Phil, Yes your right, you would need to remove part of your diving platforms I think, not much but just re shape them and maybe cut a bit more of a well in the stern were your builge pump is. Not a big job properly need a company like o I don't know Compass Marine maybe
. Or another fiberglass expert. You would need to speak to DK Collins to see how much room you really need. But really it would not be too much of a big job. Someone or we would have to take a look and quote you.
She would go well with 2 x 200HP (maybe 55/60kts +/- and like I said before it is a nice clean boat for her age!
Hard choice to make but the twin suzuki's would be the best option in my opinion. unless u want to go for merc again.
Good luck in making a choice!!