nitecapt, I am familiar with your area, I worked in town some years ago.
You need to find a good local repair shop willing to work on your unit.
I would do a little more research on sprinters and the service of. Unless things have changed the needed computer software is only avl at Sprinter dealers and Freightliner dealerships. You can't take it to a MB car dealership.
Google the hourly rate at service facilities.
I found the truck shops on the north shore look at rv's as a fun vehicle that can wait for a repair. If a regular commercial truck customer needs a repair, your rv will come off the rack and the commercial truck goes in your spot. That can cut into your rv time as it can push you back days or weeks. Been there a few times.
Having the weight of 2 slides on the Sprinter floorplan that you like is going to be a weight issue IMO. You also need to look into the Thor track record for workmanship.
The FR products like Sunseeker are not top of the line either but I would rather drop down $60/70k opposed to over $100-125k for questionable quality. A good rv mechanic can tweak up things to make it work a whole lot better. Spending less offers the needed wiggle room to tweak it up.
Have you gone to see the Sunseekers at Travel America rt 25 Commack ?
She (Suzanne) can order you one and they do repair them. Located behind Trailer City East. Its a seasonal business now, closes the shop in Nov to March.
My Sunseeker has a 14,500 GVWR and I normally roll down the road at 12,500-12,700. I bought mine out of state where I normally camp and even though I have had the usual issues, it works well enough for me. Travel America happens to have a good relationship with FR reps because she has so many rental units. She can get things done.
I don't know if you know Kevin at Cross country Trailers 670 Ft Salonga rd Northport. Its the round bldg. with a one man rv repair shop in the rear.
He might be a good person for you to talk to as well. Open all year for repair work and won't put you off.
Good luck with your decision, feel free to PM me .
Bob