The FPP only has two option for RTC. A Rasclock and a DS1305. None of these seem to be available here in Australia. Bummer!
Even DX.com sel;ls them http://aud.dx.com/product/ds3231-raspberry-pi-rtc-board-real-time-clock-module-for-arduino-black-961277258#.U3VmhCiBtuY
They are tiny. And these guys have got them going on the Pi
So I will try also.