Adioso: have you talked to ITA Software (now part of Google) about licensing QPX? We solved the data issue, very painfully, over a 10-year period, by working directly with the airlines. (This was, in fact, one of my major contributions to the company as COO, and many people were involved.) Using QPX, you could implement exactly what you envision with stuff ITA already has running.

I'm a cofounder of ITA but am no longer affiliated with the company. But if you want to talk to people there, I can connect you. Just reply here with some way for me to contact you.