Choosing the right tow vehicle

Drock, I have a 2013 2500 suburban, and almost the same trailer (less one slide, yours is only about 300 lbs more). The only concerns I have when towing is a 216* tranny temp in Houston Summer. I need an aftermarket cooler, and a heat shield where the exhaust pipe runs under the tranny pan. It pulls just fine.
I added a curt class V hitch, 2400 lbs tongue capacity. Stock tongue is only 1000 lbs. Check out my hitch here:
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28635884/srt/pa/pging/1/page/2.cfm

Looking at the old SUVs I don't think trim levels are the major player in price difference.
It's mileage and condition.
Yes a newer 2500burb will do the same as the old iron. They'll all be dogs loaded down and towing 10klbs with a gasser, so imo that doesn't even really matter.
I'd prefer something that was 5 years old over 10-15 simply for newer components = typically less nickel and dime repairs.

Thanks for all the info everyone. the payload in the vehicle consists of 2 adults and 4 kids, very little cargo. We typically travel light for camping so I don't expect the total for added weight to the dry weight to be more then 500lbs. What I found promising is that both gas and diesel Excursions and the 2500 Suburban/Yunkon XL are out there, and the prive ranges from 6k to over 30k. I don't need all the bells and whistles so really a base TV is all I need. I noticed that the 2013 Suburban 2500 (last year of the 2500s) had a towing capacity of 9600 and tongue weight rating of 1200. Would that be enough truck to tow what I am looking to get?

I did look at the 1 ton van option too. Not keen on a van though, had one in the past, just a weird and awkward feeling to drive. LOL. Although get a slick metal flake paint job and a few round bubble windows installed, may be a conversation piece.

8.1 Burb will pull a little harder than a V10. It's still the coup de gras for big block gassers (and will likely stay that way since no one makes a big ci gasser anymore).
Problem with the Burb is you get the (somewhere between meh and crappy) 4l80 trans, where with a V10 excusion after 04? you get the 5 speed torq shift. Better trans equal or more reliable engine in the V10 and super duty chassis.
Not a ford guy and apples to apples and I'd take an excursion over a Burb even with the 8.1.
8.1/Alli combo pickup might be a different story. 7.3 Pstroke excursion though ftw.
Good luck finding one though. Neighbor just spent months looking for a good excursion. Finally found an 05 V10 with 80kmi Cherry condition. Had to give $20k for a 12 year old gasser though. On the upside it has close to $3k of new Gould and fancy wheels and a sweet Expediton type roof rack. Low mile 7.3 excursions are almost like hens teeth though.

A one ton van is a great family tow vehicle, but for over 10000 lbs you will have to have either a diesel or V10 gasser for sure. You also will have to have an after market class IV hitch installed, and if you have a van full of people and gear, probably will need heavier rear springs.

The Excursion is essentially an F250 chassis with an SUV body on it. The 7.3 diesel engine from '99-'02 is an excellent choice.

Choice also depends on what you are carrying in the vehicle while towing. I'm going to assume by the model # that it is a bunk house so you will have several passengers. You need the payload to support the tongue weight plus the weight of all passengers and gear in the SUV. You may want/need to consider a 1 ton van.

The Excursion is built on a Superduty frame, so with a Diesel engine, you've basically got a diesel Superduty. If you're towing 10,000 lbs, get a WD hitch and go have fun.
They haven't made Excursions for years, so finding a good used one might be hard.

It has an unloaded weight of about 8k. That's a lot of trailer and tongue weight which will require significant payload. Not sure you can get what you will need in a used SUV.