Hi Harjit,

We use the Winbond W77C32, very similar to the Dallas DS80C320. Haven't had any trouble getting the parts here, and good support from Winbond regarding questions. It's also fast (4 clocks per cycle, up to 40 MHz). The only downside to this particular version is that it's ROMless, which we were looking for anyway. They make other variations also.

You might also look at Cynal, I believe they have dual uart parts.

Dennis