All of those options would work well IMHO...
As a 2 time owner of a Ford Excursion I'll chime in.
First of all, the Ford Excursion is a FANTASTIC combination of people hauler and tow vehicle. You have the 3/4 ton suspension with a lot of leg room inside. As long as you don't find one of the rare 5.4L Triton models, you will have plenty of power from either the 10 Cylinder Triton gas model or the 7.3L or 6.0 L PSD.
Just a note though, Ford had a myriad of issues with the 6.0L PSD, so I would be very careful before buying one. Secondly, as mentioned above, the 7.3L PSD Excursion is a rare find and finding one in nice condition with relatively low miles is probably going to be difficult to do...and you're going to PAY big time for those models. I don't know if it will be worth it in the end honestly, but that's up to you. They are GREAT vehicles, I had them both. I loved my 7.3L PSD Excursion. I still miss it today. We sold it back in 2010 to a guy who actually flew up from Georgia, because even 5 years ago they were getting more and more rare. I could only imagine how hard it would be to find one these days (keep in mind that 2006 was the last year IIRC). We just wanted a truck, since our kids were getting older and not all camp anymore and we don't need as much people room.
IMHO finding a nice gas V10 Excursion would do you very well...if you can find one.
Good Luck