I'm considering buying a bunch of US Airways miles, with their current bonus offer. Yes I know I've left it to the last minute, but please bear with me. I want to redeem the miles for SYD to either FRA or LHR (round trip) in First (seemingly the best availability is on Thai). To check availability I looked at Aeroplan which shows tons of availability for whichever date I choose, more or less. ANA, which seems to be the preferred search site shows only a fraction of the availability. Aeroplan seems to offer much more variety (10+ hour layovers for example). Which one can I trust? I'm happy to spend the best part of 12 hours in BKK if it means First all the way on TG, but I don't want to buy the miles and find I can't use them for the intended purpose. Any help would be appreciated.