I've been looking at something similar (very low on my priority list - but every now and then I get back to it); and I do not think you can use the hardware module on the PIC. You have to bit-bang your way around this. To get the higher rates, you'll need to add some additional hardware to help the PIC.

A few notes that have helped me...
Design Note 48 (I2C Bus Sniffer) - http://www.avrfreaks.net/modules/Fre...566/DN_048.pdf
I2C Bus Sniffer on AVR - http://www.radiolocman.com/shem/sche....html?di=64837