My wife and I had 2 big issues with the captains chairs, but I know there are upsides too. We planned on running much of the time without a rear seat, and with a baby in the back, we could still take a set of parents easily. The possibility of seating 5 without the rear seat was much better than 4 for our situation.
The other big thing is the bench folds into a FLAT area behind the seat, and you have a good 9 feet of FLAT area from the tailgate to the front seats. We enjoy throwing a mattress in the back and still having a big area for gear, we usually have the mattress up against the front seats and still have a big cooking/eating/whatever area under the rear hatch. The buckets so not fold completely flat, and have a divot between them. But anyways...
The factory Ex roof rack rides on some heavy duty looking rails that are set wide and mostly over the roof/side junction, they look like they should be able to support a bunch of weight with no problems.
You can throw a 3/4 mattress (wider than a twin, not quite a full) in the back of the Ex without disturbing the middle seats. Crack the front windows with vent guards, extend the rear quarter windows out. It makes a nice place to spend the night!
*with the bench seat* there are 2 LATCH points set about 10 inches apart behind the passenger bench seat, and a single point behind the middle and drivers seats. These are part of the seat frame and would remove the bench, so the captains chairs would be different. I guess it would be nice to not have to remove a childs seat to get in the rear seating row with the captains chairs, but I still like my bench! The bench is stupid wide, I am sure you could also fit 2 seats on the "60" part of the 60/40 split and still use the "40" to access the rear area. That is what I plan to do with kid #2.
300k is not a trivial amount of miles. I think Ford long blocks are in the 4-5k range. No clue how much installing one is. Honestly, if the engine looked good, sounded good, had at least some sort of a maintenance history, passed the teakettle test (take the oil cap off, place it upside down back on the oil filler, and see if the blowby on the motor was enough to make the cap move like a teakettle) and drove well, I see no real reason it should NOT last to 400k miles. You might need an injector or IDM or other random pieces here and there, but the newest 7.3 Ford put out is nearly 10 years old, so any of them may need maintenance at any time.
To save time and money, I just used the factory electric shift transfercase and wired it to work with the manual transmission. You have to replace the input shaft for the automatic transfercase to work with the manual transmission, but that input will work with either transfercase, so if I ever have problems with the electric shift, I will just get a manual shift from an auto (much easier to find) and swap in my input gear again.
I got a rebuilt transmission, paid the core charge for the manual transmission, and got a new factory Ford shift tower, boot, shift lever, clutch, clutch hydraulics, transmission midplate and a couple other bits from Joe's Transmission shipped to my local shipping dock for just under 3000 bucks. They were GREAT to deal with, even when I screwed up the boot on my transmission they sent me out another one free of charge, did not even charge me shipping. I have no financial ties to this company, but they went beyond treating me right, and would recommend them without hesitation.
http://www.joestransmission.net/
I got a slightly upgraded clutch because I use the truck heavily and I have it tuned just a little, it was 600 bucks. Nice thing is it came with a flywheel, flywheel bolts and pressure plate bolts, so it was perfect for a swap.
I got the computer reprogrammed to manual transmission and a tune added to my chip for 100ish from DP tuner.
When you add in soundproofing, incidentals, consumables, blah blah blah, I am probably closer to 4000 bucks. I should have no problems selling my used Automatic transmission for 500 bucks at least.
3500 is not chump change, but when you compare it to a 4500-5500+ dollar high end BTS or John Woods transmission, it is a bargain - besides, I just like manuals.
I am horrible at guessing labor charges, but I would guess I ended up spending 50 hours doing the swap. Much of that was scratching my head, reading and rereading wiring diagrams, and doing several revisions on my transmission tunnel. I also had to put up and take down my crossmember several times for fitment issues. I would guess I could do it again in 25-30 hours, and I would assume a shop could do it in about the same amount of time.
The trick would be finding a shop that did not look at you sideways when you said you wanted to swap a manual transmission in to an Excursion, and give you the "go away" price - you know, that unrealistically high price that they would do it for if you actually paid it, but mainly they want you to refuse it because it is too expensive because they have no real desire to mess with it!
Then again, thats why I am a Paramedic and not a mechanic!
Bottom line is these pigs are not cheap. The engine is usually fine, but the suspension needs some help from stock form, the stock transmission will go out at some point, and it had a healthy appetite for front wheel bearings and ball joints. But anything will wear out ball joints over time, and I have a spyntech front spindle kit on my truck, so no more unit bearings.
But no one makes anything like them any more, it really is in a class of 1. I guess I will keep throwing money at it. Besides, have you ever priced a new 2500 Suburban? I have a looonnnggg way to go before I am in that spending league!