Water logged 23' Tsunami Refurb Project

[Capt_Mac]

I own a 1978 23' tsunami open fisherman, the reason for me being on this forum is from what I have heard and seen is that the older seacrafts are similar to my boat. With that said, I now drive a barge rather then an open fisherman because of the water that is trapped inside of my hull. The foam filled hullis full of trapped water, stringers and transom are obviously made of wood and are rotted and causing the fiberglass and gelcoat to flex enormously. I've deciced to take this oppurtunity to go ahead and refurb and repower the boat. Now here are the qeustions:

1. How would I go about removing the bad foam and wood stingers and transom with out cutting my deck to pieces(which is in great shape)?

2. Would anybody recommend the seacast product as a core rather then marine plywood?

3. I am a Yamaha four stoke fan all the way and I would like to mount twin 200hp on a bracket with an enclosed transom, is their a weight issue here or have other 23' seacrafts already done this?

Any help would be greatly appreciated as this boat has been in my family for a long time now and I just can not give the boat up and buy one of these fast but rough 5 year life span boats. Or if their is any kind of literature or personal knowledge on my boat, that would also be great.

Fish hard and die happy!