You can get all your hoses and ends from here:
http://aeroquip.cc/index.aspx?gclid=CKzwvMTglaICFch_5Qod2i45DQ
I used the socketless ends on mine. Mine pulls from the tank to a 100 micron Aeromotive filter, then to the pump, and all those lines are -8 AN (1/2" ID). From the pump output I go to a 10 micron Aeromotive filter, then to a in line adapter for my fuel pressure gage, and then on to the engine. From the pump output to the engine is -6 AN (3/8" ID) hose. For the return from the rail to the tank, i used -4 AN (1/4" ID)hose. The AQP hose is fully ethanol compatible. Also, when running your lines, make nice sweeping curves, and use as few 90 deg fittings as possible. You can see in the photos below what I am talking about. My system only uses 1 90, where it comes out of the tank. Fewer 90s and sweeping turns makes for using more hose, but it is better from a fuel flow standpoint than pumping thru a bunch of 90s or 45s. Give this website a read, this is where I educated myself about the system and the best way to do it:
http://www.diamondmarine.com/web_pages/Fuel System.htm
When I first got mine, it did not have a pre pump filter, and the pump was zip tied to the rear seat support tube in the center compartment. It just pulled from the tank to the pump, and then thru a WIX 33093 filter. So you can put it there, and it works and is out of the way, but I didnt like it there, so I had a plate made that spanned the bilge area and mounted all the filters and pump to that plate, then screwed the plate to the floor.
Make sure you wire the pump with a relay. I used this one from painless wiring, since it is waterproof:
http://www.painlesswiring.com/webcatalog/largeview.php?SearchField=30130
To wire it, you pick up a key on source from the key switch and run a wire from there to the "turn on" wire of the relay. Then run pos (thru a 20 amp resettable breaker) and neg from the battery to the relay and run pos and neg from the other wires on the relay to the pump. That way you are not running a bunch of amps from the battery to the dash and back down the side of the boat to the pump. The pump can draw a decent load, so its best to do it with a relay.
For the hardware to mount the pump, I got it from this website. The first link is the base page with all the different systems, and the second link will take you to the fuel pump page:
http://www.boats.net/parts/search/Merc/High Performance/2005/1925211DH/parts.html
http://www.boats.net/parts/search/Merc/High Performance/2005/1925211DH/FUEL PUMP/parts.html
I bought parts 2-5 on the list, but you dont need that stuff if you mount the pump to the support tube.
I also didnt like how the feed line from the tank works. It is a standpipe that sits down in the tank and has a hard 90 on the top, which is bad from a fuel flow standpoint, plus you get no gravity feed from the tank, which helps to keep the pump from cavitating. So I pulled the standpipe out of the tank and put a fitting in there to seal it up. Then I drilled the bottom of the tank to accept a -8 AN fast flow fuel fitting, so I pull fuel from the bottom of the tank. That way it it keeps the pump and thus the 280 fed well.
I got my fuel pump from Diamond Marine, but Brucato is as good a place as any. I got the fast flow thru tank fitting, filters, and the filter mounts from Summit Racing or Jegs, I cant remember which.
Check ebay for a shop manual, or look around online for one. Someone usually has one they dont need, and Merc prices for the manuals are pretty high.
For your trim lines, find a place that makes hydraulic hoses near you and have them custom make you some hoses, mine cost about 15 bucks each. And do yourself a favor and spend another 20 bucks on some hydraulic quick connect ends for the pump. That way if you have to remove the pump for some reason, you can easily pop the lines loose and not risk stripping the pump body. Take your pump with you so they can match up the lines, and take a photo and some measurements of the motor ends so they can match up what you need on the hoses. You need to use hoses that are 100R7 rated or better.
I am not sure what you mean with the #6 pin, so I am going to skip that question.
As for trim pump mounting, mine is mounted on the starboard side wall of the center compartment. I drilled thru the compartment and use a backer plate for strength. When I wired the trim pump, I wired directly to the relays. It was easier than trying to wire to the plug that goes into the pump. I just cut the wires off flush with the end of the plug and put liquid neoprene on the exposed ends to seal them up and then plugged the plug into the socket to seal it up and keep it from corroding.
This is a top view of the fuel pump mounting, and you can also see the trim pump quick connects:
Here is a view of the pump mounting that shows the lines (you can also see the dummy plug for the trim pump):
Trim line attachment to the engine:
Trim pump mounting in center compartment (you can also see the rear seat support tube):
