I haven’t towed a camper yet, but I have towed several heavy utility trailers (carrying stuff) that were almost double the 1,900 pounds you’re looking to tow, and my car did just fine. I imagine either the Wilderness or the Onyx XT would do the job just as well. With the Wilderness (4.44 vs. 4.11) you get a higher final drive ratio when compared to all other Outback XT trims, so that helps the Wilderness trim have better low-end torque and (I think) slightly better throttle response.
If you plan to tow extensively, I would highly recommend the OEM hardware over anything extra. The OEM connector only comes with a 4-pin connector, so you’ll need to purchase a 7-pin connector plus the aftermarket brake controller, but the OEM connector is significantly better designed, so it’s worth the extra cost.
The only other thing to keep in mind is that when pulling, you are required to use a minimum of 91 octane (or higher). However, it’s worth noting that if Climbing is important to you, then you’re free to run 87 octane all the time even when towing. But whichever Outback model you’re looking at will be more than capable of towing a 1,900-pound trailer.
