Hi there,

Please clarify if you intend to use the IR as medium of Transmission only or intending a full blown IrDA interface for your PIC. Microchip makes a chip that has the IrDA stack built into it. I don't recall the number but will post later.
If you intednd only a simple communication then select a PIC that has an onboard PWM generator (for theTx part anded with the serial data and thrown to an IR LED)and use a TSOP1736 or similar IR sensor-decoder to interface as the receiver.

Regards

Sougata