The Trailfinders service charge is a bit of a rip-off, in my case they didn't disclose it in advance then added a similar charge per person! I canceled the whole itinerary and booked with ebookers instead, they had a 35 EUR service fee at the time.

I would have bought it from AA but they did not have time to issue the paper tickets.

Any OW airline should be able to issue a xONEx, AA is recommend.