Hi and welcome. Good luck finding an XT. In my opinion they are the italian supermodels of Subarus: They look great and the performance is amazing, but they can be fussy, high maintenance and expensive, at least relative to a regular wagon.
I suggest you read this thread:2005 Outback XT Limited with 102k.
You can learn a lot.
Overwhelmingly, the most important thing to look for is a complete set of maintenance documentation from the previous owner(s). These cars can last a long time if cared for properly, but the sting is that they will get into expensive problems FAST if someone skimped on the upkeep. Regular outbacks are more forgiving in this regard.
New turbos on old engines can be a red flag, or a blessing. It has happened before where a turbo died and the owner just threw a new turbo into the car without addressing the source of the problem, and this can lead to serial replacements or even a chain reaction that takes out the whole engine. On the other hand, sometimes it gets done the right way and you'll get extra value from having low miles on the turbo.
That link will tell you about the importance and expense of the 105,000 mile maintenance job.
Both transmissions just work- no special concerns come to mind. The manual needs clutches like any other, the auto needs fluid changes like any other. Get the one you'll enjoy driving the most.
So find one, test drive it, make sure the paperwork is complete. If there are gaps (or no paperwork) this is your play to negotiate a major discount or gain a strong warranty.
I'd strongly advise you to hire an inspection mechanic once you've got a candidate.