Congratulations on your new Airstream! A 27’ Airstream will have an actual tongue weight close to 1000 lbs. I have a Sherline scale and our 2019 27’ Globetrotter came in around 1100 lbs with a full tank of fresh water and full propane.
What do you plan to tow with? You’ll want to watch your payload capacity of your tow vehicle - check the door sticker. Payload includes what ever is inside your tow vehicle plus the weight of the trailer on the ball. Weight distribution hitch does not factor into payload calculations. We started with a 2019 Ram
1500 but found the payload was only 1220 lbs. Pulled it just fine but was too close to the rear axle max so we upgraded to a 2500 with 2940 lbs. payload. Problem solved!
There are lots of good WD hitches out there; you’ll get lots of opinions on what’s best. Short answer is they’ll all do the job if set up properly. We’ve got a Blue Ox Sway Pro with 1500# bars. Once you get your hitch, head to the CAT scales and do a three pass method. One with WD enabled, one disabled and last, truck alone. This will tell you how much weight is getting transferred to the front axle and trailer.
More importantly, it will tell you if you’re over the TV’s axle ratings. Those can be found on the other door sticker and should be considered most important.
I don’t think Airstream will do anything on the mattresses - but the Tuft and Needle ones in the Globetrotter are really nice, much better than the standard ones. Same thing with the wheels - what you see is what you get. Some people upgrade to a 16” wheel and Michelin tire but that’s a dealer installed option. And, no trade-in credit for the original wheels. You get to keep them. The new Goodyear Endurance 15” tires are much better than the old Marathons so just wear them out then decide.
Hope that helps get you started. Happy Camping!