Congrats on the boat. They're hard to find
Regarding the rear seats, you'll probably have to come up with your own alternative, maybe something from Liebroc, or just a pair of bean bags.
That hull loves to run around 30mph, she's heavy an II was getting 1.1-1.3 mpg on my 09 250s before we repowered, the new 250s were more fuel efficient.

Good luck with the project.