For my 17 Campion Red Hot I had built a fish hold between the stringers in between the sleeper seats. Worked great. I built an aluminum frame on which a 1.2 x 0.5 x 0.4 m stainless trough sat. The trough was removeable with no drains. But below the trough was the open channel between the stringers to the bilge - in case of a spill - easy clean up. The trough sat recessed deep enough to fit a 1/2" ply stainless framed lid on top for walking across. The total fish storage was maybe not quite as much as currently in yours but close I'd say. It maxed out the space between the stringers. It wouldn't fit any halis over 20 lbs though. The nice thing about such a removeable trough is that you don't need to transfer your catch into a tub, bag or bucket to carry it to the fish cleaning station.
Good luck, I am sure you'll come up with a good idea. Can't wait to see it!
Good luck, I am sure you'll come up with a good idea. Can't wait to see it!