I haven't towed a camper yet but I have towed some heavy utility trailers (carrying stuff) that were almost double the 1,900 lbs you are looking to tow, and my car did fine. I imagine either the Wilderness or the Onyx XT would do the job just as well. You do get a higher final drive ratio with the Wilderness (4.44 vs. 4.11) 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 hitch instead of anything aftermarket. The OEM hitch does only come with a 4-pin connector, so you would have to get a 7-pin connector plus brake controller aftermarket, but the OEM hitch is significantly better designed, so worth the additional cost.
The only other thing to keep in mind is that when towing, you are required to use 91 octane (or more) minimum. It is worth mentioning, though, that if the Ascent is of any consideration to you, then you are free to use 87 octane all the time even when towing. But either of the Outback trims you are looking at will be plenty capable for a 1,900 lb trailer
If you plan to tow extensively, I would highly recommend the OEM hitch instead of anything aftermarket. The OEM hitch does only come with a 4-pin connector, so you would have to get a 7-pin connector plus brake controller aftermarket, but the OEM hitch is significantly better designed, so worth the additional cost.
The only other thing to keep in mind is that when towing, you are required to use 91 octane (or more) minimum. It is worth mentioning, though, that if the Ascent is of any consideration to you, then you are free to use 87 octane all the time even when towing. But either of the Outback trims you are looking at will be plenty capable for a 1,900 lb trailer