There's nothing wrong with buying OWE tickets from a reputable travel agent. The two questions I'd be asking is "is the agent honest?" and "does the agent know enough about OWE rules to be useful?".

If you're comfortable with the rules yourself you can do most of the setup with the "local" BA rtw desk (who surely has means of dealing with hearing-impaired travelers), with only a couple of fax'es going back and forth to IST.