I just got one like yours but 2002 same engine and stuff, it is fun.
I wish I had the same idea before I throw away all the seats.......
I just took the floor off since it was full of water although not visible but when I took the seats and push hard against the floor I started to see water and to my surprise the floor is aluminium so if not really rusted so Is not going to be much work for rustproof it and to start to build the frame for the new floor.
next is to take those rivets....
good luck with your project