I have been searching for ATMEGA328P-PU for my phi-panel kits so here is FYI:
http://www.newark.com/atmel/atmega328p-pu/ic-8bit-mcu-megaavr-20mhz-dip-28/dp/15R0268
The above have US distributions. Clear winner (w/o shipping) is mouser for small quantity ($3.5 each) or medium quantity (up to 25 for $3.05 each) and digi-key wins if you want 100 chips ($2.78 per chip). Thought someone may want to know this. None of the above had arduino boot loader.
With bootloader: