I am getting a magazine called Cure http://www.curetoday.com/ and they had an interesting article on Iressa. Some facts:
It is only indicated for lung cancer and only after failure of other forms of chemotherapy.
It was developed for adenocarcinoma.
It targets mutations in a specific region of the epidermal growth factor receptor (EGFR). These molecules produce tumors "that are exquisitly sensitive to treatment with Iressa".
Only 10% receiving it have any response - mostly women. Some (lung cancer) patients have had a rather dramatic response to treatment.

It may be a long shot to be prescribing it for oral cancer patients. But subsequent data may prove that wrong.

I can't answer your question about other chemo combinations. Some here have tried Zeloda which is an oral form of F5U.