If you haven't made your TT choice yet, how about a Kodiak Model 300BHSL? Similar lay-out as your first choice (if not identical), and 8900# GVRW / 833# dry hitch.
I tow a 2012 Kodiak 263RLS with a 2004 Expy EB, with Tow package. The Achilles' heel of the Expy is its rear axle and the RGAWR (4128 lbs base, 4250 lbs EL); the tongue weight added to the passengers and cargo quickly adds up.
Last summer's heaviest trip was as such: TT 5836 lbs dry (weighted), fully loaded 6226 lbs (weighted). Tongue loaded weight was approx. 800 lbs (weighted with a Shurline scale). With pax (2 adults, 3 kids) and cargo inside the Expy (75 lbs ), the RAWR was within 10 lbs ... With such load, the truck was at max. payload (1450 lbs ).
I'm aware of the loads and limits of the SUV; it pulls great, breaking power is in tune (truck and TT with Tekonsha P3), rear end is not sagging (WD hitch,), and sway is under control with adjusted weight distribution, Load E tires with proper pressure and a Reese DC anti-sway setup.
Your Expy, though being a EL has similar weights as mine; it can take and handle some heavy loads, I would not worry. It does has a few advantages, having a longer wheelbase will actually improve the handling, a more powerful engine and a 6-speed tranny. Just be careful with the payload: with up to 8 passengers and cargo, it can add up quickly.
1200 Lbs TW may be a tad too much, but 12%-15% of 7500 Lbs equals 900-1125 Lbs which would be too much for my Expy's WDH (max. 895 Lbs tongue).
The OP's trailer looks very similar to mine, and I have to be very careful when loading both TV and TT (hence the Shurline scale). I hope to find a 2500 Suburban someday...
I'd be careful with your trailer load. I tow a 2012 Kodiak 263RLSL with a pin weight of ~800 Lbs (from a Shurline scale; dry: 670 Lbs), 6200 Lbs of ready-for-camping trailer. With the Wife and Kids (3) onboard and fully fueled up, my 2004 Ford Expedition EB is at the max RGAW of 4128 Lbs and max GVWR. The truck's payload stands at 1425 Lbs.
I've traveled Highway 30 a few times with my TT this summer from Mercier Bridge to A15S. Not much to say except traveling on such perfect roads is a joy - remember, this is Quebec, and we are not used to new roads...
To complete the ring, only the St-Lawrence River toll bridge at the far west portion of the highway was missing, and this opened a few weeks ago. I haven't tried it yet (TT in winter storage) but will do next spring when we head back to Lake Champlain.