Farallon's website is garbage. They need to add build specs and performance specs.
You said 5100 dry weight. What is the beam and deadrise?
More beam and deeper V both require more HP.
My boat is about 26' 6" (discounting the bow pulpit). 8.5 foot beam. 19 degrees at the transom. Hardtop and...
Given the options you outline, I'd go 2x200hp.
Adding a kicker with controls and steering and AP? All that stuff adds up quick. Twin 200s shouldn't be that very much more than a Df300b plus kicker and accessories.
I've been running an Axiom9rv for the last 4 years. I don't recall ever losing GPS position. First edition with internal antenna.
I also run an A78 and A50d on a different boat. One or the other occasionally drops position but quickly requires. Since those units are obsolete, that point is moot...
Pro-Line 251 or 27 Walk. 1997 and newer are wood free hulls and decks.
My 1998 251 is still going strong. 8'6" beam. 175 gas tank. Enclosed head. Stove top and fridge.
That said, there are some compromises. Sitting on the head is tight to the knees. Filler cushion required to sleep 2 in the V...
I don't ever lose GPS but it seems like it is taking longer to get a fix than when my Axiom was new.
I have mine paired with a Quantum Wi-Fi radar ( only run a power cord to it), Evo 100 autopilot, CP370 sonar module and TM260 transducer. I would add another Axiom 9 but I'm out of room.
I installed mine in 2017. Trouble free. Very fast chart re-draws. Pages and data boxes are very customizable.
Chirp sonar and Downvision are very good. I don't use side scan or 3D much.
One thing I don't like is the chip slot is in the back; pita to do updates if it is flush mounted.
Not to open a can of worms.......But,
My 2006 had an ECU recall. I don't remember the reason for it. That said, your 2005 probably did also so the hours read off the ECU may be less than actual on the engine.
Your compression test is good. The mechanic gave the engine his endorsement, right...
I have a 2017 Df300ap with 800 hours on it. I did my first compression test at 200 hours to establish a baseline.
I didn't have a service manual at that time to follow but this is how I do my check.
Engine is cold and all plugs removed. I thread in my compression gage and hit the starter button...
First of all, the Simrad sensor can only be connected to the nmea 2000 network. You can not connect it and also have the older analog fuel gage also hooked up.
It also needs to be calibrated by using a Simrad/Navinco based MFD or display ( Suzuki C10 engine display works in this regard).
"Anchovies for albacore...?"
Unless you have 4 or 5 guys on the boat, the troll to bait stop is hard to accomplish.
I made a bait tank out of a 35 gallon plastic barrel. 800gph pump. It worked great! Near zero anchovie losses.
Go to a good plumbing supply store and ask for tank fittings. These...