If I
ever get tired of my 251, a boat like this would be my dream replacement

First, take the 29 SS hull. Long and narrow, deep V for good running and cutting a chop and fuel economy. With a 9 foot beam, it is still very trailerable.
Add a minimalist cabin. "V" berth to sleep 2 comfortably and plumbed head. No partition for the head. No sink. No stove. No refrigerator. Maybe a microwave to heat hot coffee and simple prepared meals. Geared for a couple of guys or couple on a fishing weekend, no frills just function. A screened hatch and a couple of portholes for ventilation. LED lighting. Good storage under the berth
A helm and seating similiar to the 251 for 4. Twin swivel helm chairs with built-in tackle trays and storage spaces below. Seating for 2 behind. An XP enclosure or a windshield that is high enough to look thru and not over with integrated hardtop and overhead storage. Either a large lockable dash box for electronics or area for flush mounted electonics. No side saddle seats. Hand holds and room for a crew of 4 to stand up and pound out the ride if need be.
The cockpit would be optimized for fishing, in concert with the minimal cabin. Narrow aft transom gunwale. Large macerated fishboxes. Dual round insulated livewells tucked into the aft corners (I really like the one on my 24SS!), separately plumbed and pumped. Either could be used as a drainable cooler. How about insertable tuna tubes??? Maybe a flip out sink from the transom or a sink that juts aft towards the motor well? 3 rod holders a side. Some gizmo or holder insert that would facilitate rods trolled on the horizontal and out from the side of the boat?
Other musts: Dual windshield wipers. LED nav lights. LED helm and cockpit courtesy lights. Integrated anchor roller. Fresh water washdown. Raw water washdown (no shared pump). Trim tabs standard. Hardtop rocket launcers-6 minimum.
Warren